DSE Econ Ch1 校本教材(TLHK S4 Economics)Node Report

Source: TLHK S4 Economics 校本 worksheet(Ch. 1 Basic Economic Concepts)。與 Pearson Exploring Economics Book 1 分析(見 dse-econ-ch1-basic-concepts.md)分開存放,因材料來源不同——校本教材為第一優先,定教學進度(見 study-methodology-layers.md 材料來源優先序)。

跨來源核對慣例:每題/每個 Case 分析後,主動核對是否與 Pearson 檔案已記錄的 node/relationship 重疊或呼應,標記「跨來源確認」或「新增 node」,以便充分利用兩份材料互相印證。

Established 2026-09-05。頁碼依校本教材原文(P.3–P.7、P.12–13 已覆蓋)。

1. Section 1.1 Wants, Scarcity and Choice(P.3–5)

TOC 對照:校本教材完整目錄(P.3)為 1.1 Wants/Scarcity/Choice、1.2 Opportunity cost、1.3 Goods、1.4 Economic Activities、1.5 Interest、1.6 Circular flows、1.7 Scarcity, competition & discrimination、1.8 Economics as a social science。對比 Pearson 骨架(6個結構node+2個分支),1.7 與 1.8 這兩個 topic 未曾在 Pearson 分析中出現——後續頁面需留意這兩節內容,判斷是新 node 還是既有 node 的延伸應用。

Node A: Wants — Definition: human desires for things(material/non-material)。Property: unlimited,satisfying existing wants causes new wants to arise,so human wants can never be fully satisfied。

Relationship tested(新細節,未見於 Pearson 骨架):wants 只需要 willingness,不需要 purchasing power("Wants focus on our willingness only. Need not be backed up by purchasing power")。這是預先埋下的伏筆 node——為後續(可能在市場需求章節)區分 wants vs demand(demand = want + ability to pay)作準備,demand 的正式 node 要待後續章節驗證。

Node B: Limited resources — We need resources to produce goods/services satisfying wants;resources are limited → limited goods/services can be produced。

Node C: Scarcity(稀少性) — def: unlimited wants + limited resources ⟹ as long as the quantity available of limited resources are insufficient to satisfy unlimited wants,scarcity takes place。

Relationship tested(Robinson apple example): scarcity requires BOTH components — (i) a want must exist for the resource,(ii) quantity must be insufficient relative to that want。若(i)缺席(Robinson dislikes apples,no want),apples are NOT scarce to him,不論數量多少;若(i)成立且數量不足((ii)),apples ARE scarce。→ Scarcity is a relative concept,not an absolute quantity measure。

Relationship tested(rich vs poor): scarcity is universal — both rich and poor face it,因為(i)(unlimited wants)對任何人都成立,「只有窮人才有稀缺問題」是常見誤解。

Relationship tested(technology evaluation question): 增加產量不能永久解決 scarcity,因為這說法否定了(i)——Node A 已定義「wants satisfied → new wants arise」,unlimited wants 恆常成立,增加供應只會滿足現有 wants,新 wants 又會再出現,scarcity 持續存在。直接借用 Node A 的「never fully satisfied」屬性作反證機制。

Node D: Implications of scarcity → Competition & Choice(兩條並行分支,新結構元素)

Competition(競爭):people compete to obtain more resources/goods(例:大學學位按 DSE 成績分配)——校本教材標明「will be discussed in part 1.6」,需後續頁面驗證此 node 如何接落 circular flow 或 1.7 scarcity/competition/discrimination。
Choice:people must choose to better utilise scarce resources(例:Ms. Leung 有 $300 現金,但想要 4 款專輯封面,預算不足以全部購買)。

Relationship tested(Student A/B test-yourself box): 因果方向為 Scarcity → Choice,單向不可逆。Student A(scarcity 導致 choice)正確;Student B(沒有 scarcity 仍要 choice)錯誤,因為沒有 scarcity 即想要的東西都能擁有,不需要作選擇。

💡 跨來源確認:這個「因果方向不可逆」測試,與 Pearson Case Analysis Q2(B)/Q3(A) 已記錄的「逆邏輯」陷阱屬於同一個 node 關係在獨立來源再次確認,加強了「稀缺性→選擇→機會成本」這條骨幹的不可逆性是本章高頻考點的信心。 💡 結構差異:校本教材將 Competition 列為與 Choice 並行的 scarcity implication(而非 Choice 之下的延伸),與 Pearson 骨架僅有「Scarcity→Choice→OC」單一鏈不同——需留意後續 1.6/1.7 頁面,判斷 Competition 是否為獨立於「個人層面 Choice→OC」之外的社會/市場層面資源分配機制,暫不與 Choice 合併。

2. Section 1.1(D)+ 1.2 導入(P.6)—「What is Economics」+ Logical Flow 圖

D. What is Economics? 三題 true/false/uncertain 判斷:

(a) "study about how to get rich" — FALSE:economics = study of human behaviour in using SCARCE resources to satisfy UNLIMITED wants,唔關「致富」事。
(b) "study about how to eliminate scarcity" — FALSE:resources 恆常 INSUFFICIENT,scarcity 永遠無法 ELIMINATED,economics 教唔到人消除 scarcity。
(c) "study about how to get most out of limited resources" — TRUE:economics 正正是研究點樣運用 scarce resources 滿足 unlimited wants,即點樣攞到 limited resources 嘅 MOST。

💡 同一材料內部重複確認:(b) 用嘅推論同 P.4「科技提升產量能否解決 scarcity」嗰題完全同一個機制(wants unlimited → scarcity 不可消除)——呢個 node 喺校本教材內部已經重複測試兩次,顯示佢係 1.1 節嘅核心反覆考點,唔止跨來源(Pearson)confirm,連校本教材自己都會反覆用同一個定義去 falsify 唔同講法。

1.2 Logical flow of Economics(圖表):Causes(Unlimited wants + Limited resources)→ Problem(Scarcity)→ Consequences(Opportunity cost → 箭頭向上 → Make choice)。

💡 呢個圖表係 Node A→B→C→D 骨幹嘅視覺化確認,同時將「Opportunity cost」同「Make choice」兩個 consequences 用箭頭連埋一齊(OC 指向 Make choice),暗示兩者係緊密配對嘅一組結果,唔係嚴格線性嘅「先choice後OC」——留意呢個佈局同 Pearson 骨架「Scarcity→Choice→OC」線性寫法唔完全一致,值得留意後續 1.2 內文點樣描述兩者關係。

3. Section 1.2(A)What is opportunity cost?(P.7)

Opportunity cost = the highest-valued option forgone("forgone" 校本教材親手註解 = "give up")。

Worked example:Ms. Leung 有 $10,000,想買 4 件商品:Digital camera $10,000、iPad air $10,000、Smartphone $10,000、Notebook $11,000(劃掉,超出預算)。

新 node:affordability 界定 choice set — Q: "Is the notebook an option of Ms. Leung?" Ans: money NOT ENOUGH → NOT her option/choice。負擔唔到嘅選項,喺比較「邊個係最高值放棄選項」之前就已經被排除,根本唔會進入計算。

💡 跨來源確認(同一 attribution slot,唔同過濾機制):呢個同 Pearson 12-node 邏輯圖(第7節)嘅「界定choice set」attribution slot(Q4 沉沒成本:過去已支出 → 唔算放棄選項)係同一個歸屬槫位,但過濾原因唔同——Q4 係「已經發生,追唔返」,呢度係「從來冇負擔能力,唔算真正選項」。兩個機制都指向同一個結論:某啲選項喺分析OC之前就要被剔除,唔會進入「放棄選項」嘅比較清單。

Preference order table(3件可負擔商品):1st=Digital Camera,2nd=Smartphone,3rd=iPad air。文字明言:"goods with same prices may give different values to buyer"——三件商品價錢完全一樣($10,000),但 value 唔一樣,呢度證明"highest-valued" 講嘅係主觀價值(preference),唔係價錢本身。

💡 新細節:之前 Case 1–6(Ms. Leung 買相機情境)全部用「收入金額」嚟代表 value(補習$200 vs 精品店$150),容易令人以為 OC 嘅 "value" 就係「金錢數字」。呢度用 preference order(1st/2nd/3rd 排序,價錢相同)先至清楚顯示:value 係主觀偏好,金錢金額只係其中一種呈現方式,唔係定義本身。

兩步程序再次出現:選咗 Digital camera(1st)→ 放棄選項 = Smartphone(2nd)+ iPad air(3rd)→ 最高值放棄選項 = Smartphone(排除已選之後,餘下最高嗰個)→ OC = 放棄 Smartphone。

💡 跨來源確認(第4次出現):兩步程序(刪除已選選項 → 餘下最高值)已經喺 Pearson Case Analysis Q1、Applications Case 2 出現過,呢度係第4次確認——首次以「preference ranking(次序)」形式呈現,唔再係純粹金錢金額比較,證明呢個程序唔限於某種 value 呈現方式,係呢一章最高頻嘅機制,冇之一。

4. Section 1.2(B)(C)Why only the highest-valued option counts + 選擇準則(P.8)

B. Only the highest-valued option forgone is the cost. 文字解釋點解 smartphone、iPad air 唔會兩個都算 OC:金錢($10,000)本身就係 limited resource,就算唔買相機,佢嘅錢都NOT ENOUGH買晒所有選項,$10,000 只夠買 ONE of the options forgone——所以 SMARTPHONE(最高值嗰個)先係買相機嘅 cost。

💡 新增(首次見到"為什麼"呢一層解釋):之前所有出現嘅「兩步程序/只計最高值」都係直接畀規則同答案,呢度係第一次見到校本教材解釋呢條規則背後嘅原因——因為預算本身有限,一次過只可能實現一個放棄選項,唔可能同時「攞埋」兩個都forgone咗嘅選項,所以加埋佢哋嘅value冇意義。呢個解釋補強咗之前淨係死記規則嘅理解深度。

C. Always choose the option with the lowest opportunity cost. 比較表(根據 preference order 1st=Camera、2nd=Smartphone、3rd=iPad air):

Chosen option	Opportunity cost
Digital camera	Smartphone
Smartphone	Digital camera
iPad air	Digital camera

According to Ms. Leung's preference,OC of buying digital camera is the LOWEST → should choose the option with the LEAST cost。

💡 新綜合node:OC最小化準則 = 選最高偏好等價。呢個表證明一個內部一致性:揀返自己preference排第一嘅選項,佢嘅OC永遠係全部選項入面最低嗰個(因為forgone去到最高只會係第2位,唔會再高)。呢個唔係新機制,而係將已知嘅「兩步程序」引伸做一個決策準則嘅驗證,值得留意但唔算獨立node。

Past exam question(HKCEE 2011 Q2,官方考題,第三個獨立來源):一幅地可建 HSR/highway/tunnel/cultural hub,對應回報 $800,000/$750,000/$650,000/$550,000。求 highway 同 tunnel 各自嘅OC。

Relationship tested:兩步程序應用喺兩個唔同嘅chosen option,但forgone set入面都包含同一個「常勝者」HSR($800,000,四者最高值)——只要HSR未被選,佢就一定係嗰次比較嘅最高值forgone。所以:highway嘅OC=HSR($800,000);tunnel嘅OC=HSR($800,000)。答案 D($800,000...$800,000)。

💡 跨來源確認(第三獨立來源):兩步程序喺 Pearson、校本worksheet 之外,喺官方 HKCEE past paper 都出現——三個獨立來源都以呢個機制為核心,進一步確認呢個係全單元最高頻、最核心嘅測試機制。 💡 新細節(固定最高值選項嘅重複命中):呢題突顯一個之前冇明確標記嘅現象——當某個選項嘅value恆常係四者最高(HSR),佢會喺唔同嘅chosen option情境下重複成為forgone最高值,即OC對唔同chosen option可以出現相同數值,呢個係「單一最高值選項壟斷forgone角色」嘅具體案例,同Applications Case 4(新選項超越)屬同一個機制嘅唔同呈現方式。

5. Section 1.2(D)Changes in values → changes in OC(P.9)

延續 P.7/P.8 preference order:chosen=Digital camera(1st),highest-valued forgone=Smartphone(2nd),third option=iPad air(3rd)。

1. Change in chosen option:相機送tripod,value of camera(chosen)INCREASE。對smartphone(forgone)冇影響。→ highest-valued option forgone REMAINS UNCHANGED → OC REMAINS UNCHANGED。

💡 跨來源確認:呢個「被選選項自身價值變化 → OC無影響」,同 Pearson 第5節已記錄嘅「三種node狀態變化」入面「被選選項自身變化(無影響)」完全一致,喺校本教材再確認一次。

2. Change in highest-valued option forgone:smartphone送一年保養,value INCREASE → OC of camera INCREASE。基本關係(OC同forgone value同向變動)嘅直接應用。

3. Change in the third option: a. iPad失去視像會議功能,third option value DECREASE。因為highest-valued forgone(smartphone)REMAINS UNCHANGED → OC REMAINS UNCHANGED。

💡 跨來源確認:同 Applications Case 5(精品店已被支配選項降值,OC不變)完全一致嘅機制,第4次以上確認。

b. iPad加AI功能,third option value INCREASE。題目問:「Does it affect the OC of choosing digital camera?」——留白,未有標準答案。

💡 格式升級,值得留意:呢題冇畀具體數字,逼學生自己講出條件式規則("It depends — only if the third option's new value now exceeds the current highest-valued forgone option, OC will change to match it; otherwise OC remains unchanged"),而唔係好似 Case 5/Case 6 咁畀具體數字要求計出確實答案。呢個係同一個「臨界值」機制(Case 5/6已confirm),但由「計具體答案」進化成「講出抽象規則」——顯示校本教材由計算層面過渡到概括層面,係值得留意嘅出題手法升級。

6. Section 1.2(D)(續)第三選項臨界值規則正式化 + Mind map總結(P.10)

延續 P.9 3(b)嘅留白問題(iPad加AI,third option value increase,「Does it affect OC?」未有答案)——P.10 正式畀出兩個分支答案:

若 iPad air 新值 higher than smartphone → highest-valued option forgone 換咗做 iPad air → OC increases(因為新forgone更高值)
若 iPad air 新值 still lower than smartphone → highest-valued option forgone remains unchanged(smartphone)→ OC remains unchanged

💡 上一輪預測應驗:呢個正正係我哋上一輪分析 P.9 3(b)時預測嘅「條件式規則」——「要視乎新價值是否超過現有最高值forgone」,而家校本教材親自畀出正式雙分支答案,同我哋嘅預測完全吻合。

Mind map:change in the value of options(總結圖表)——將之前分散嘅觀察(Case 5/6、P.9的1/2/3a/3b)正式歸納成一張統一結構圖:

Change in chosen option → OC(remains unchanged,恆定規則)
Change in highest-valued option forgone → increases則OC increases;decreases則OC decreases(同向規則)
Change in third option → surpasses highest-valued forgone則OC increases(換人);still lower則OC remains unchanged(無影響)

💡 確認性總結node:呢張 mind map 唔係新機制,而係將 Case 1-6(Applications)+ P.9 全部個別觀察正式歸納做一個統一決策樹——證明我哋跨題目逐個記錄嘅「跨來源確認」呢個做法,結果同校本教材自己嘅官方總結完全一致,方法論驗證成功。

7. Section 1.2(E)Opportunity cost = full cost of a decision(P.11)

新情境:Digital camera $10,000、iPad air $9,500(首次出現唔同價格,之前P.7-P.9嘅preference order example全部用相同價$10,000,呢度先暴露「唔同價」情況)。

Q: What is the OC of buying digital camera? Ans: a iPad air AND $500 for buying something else(例如手袋+文具+晚餐等)。

💡 新node:唔同價選項嘅OC複雜化——之前所有例子(preference order、Case 1-6)嘅選項都用「收入」或者「相同價錢」比較,forgone option嘅value可以直接讀出。呢度首次揭示:當被選選項比forgone option貴嗰陣,OC唔淨止係「forgone option本身」,仲要加埋「差價可以買到嘅其他嘢」(差價$500本身都有自己嘅opportunity cost)。

簡化慣例:"To simplify the answer, we always express the OC in terms of money" ——避免逐項列出(iPad+手袋+文具+晚餐...),直接用金錢總額表達OC。(空格留白,合理推斷答案為$10,000,但材料未見手寫確認,不作實答。)

Full cost = explicit cost + implicit cost = money cost + time cost/income forgone(兩條公式並列,標明「or」)

explicit cost = money cost = out of pocket cost(例:money paid for goods)
implicit cost = time cost/income forgone = hidden cost(例:time for queuing up,income forgone due to give up working)

💡 關鍵缺口填補:呢個圖表直接解答咗我哋喺分析 Applications Case 1 vs Case 2 時留低嘅懸案——Case 1 用「money cost + time cost」,Case 2 轉用「explicit cost + implicit cost」,當時我哋標記「需要前10頁內容確認呢兩組用語是否等價」。P.11 依家正式確認:呢兩組公式係同一件事嘅唔同講法,一一對應,唔係校本教材前後不一致,亦唔係獨立概念。

8. Section 1.2 Applications:Ms. Leung Digital Camera Scenario(Case 1–6,P.12–13)

Base scenario:besides paying money, Ms. Leung queues 2 hours to buy a digital camera. Alternative uses of the same 2 hours: private tutor($200)or boutique shift($150)。

Case 1 — Introduces opportunity cost = money cost + time cost,where time cost = "the best alternative use of time"(single alternative,no competition between options yet)。Node: the time-cost component is the value of the single best alternative use of the resource,not a sum of everything given up。

Case 2 — Two competing alternative uses of time introduced simultaneously(tutor $200 vs boutique $150)。Formula relabelled: opportunity cost = explicit cost($10,000 paid)+ implicit cost。Relationship tested: implicit cost = value of the highest-valued forgone alternative(tutor $200),NOT the sum of both forgone incomes。

Case 3 — Explicit cost removed entirely(won via lucky draw,$0 paid),implicit cost still applies(2 hours still given up)。Relationship tested: opportunity cost exists even absent any money cost — isolates implicit cost as a stand-alone driver。Answer: OC = $0 + $200(tutor still highest forgone)= $200。

Case 4 — A third alternative appears(new part-time job,$300 for 2 hours),exceeding both existing options。Relationship tested: new option becomes the new highest-valued forgone alternative → implicit cost shifts from $200 to $300。

Case 5 — The boutique income(never the highest,$150 < tutor $200)decreases to $100。Relationship tested: a change to an already-dominated(non-binding)alternative has NO effect on opportunity cost,because it was never the relevant forgone option。OC remains unchanged at $200(tutor)。

Case 6 — The boutique income increases to $350,now exceeding tutor($200)。Relationship tested: mirror of Case 5 — the changed alternative now surpasses the current highest,so it becomes the new binding forgone option。OC shifts from $200(tutor)to $350(boutique)。

💡 跨來源確認:Case 5 vs Case 6 係「一問兩考、方向相反」呢個組合工具(Pearson MC Q9、Case Q4 已記錄)在獨立來源再次確認。 💡 新組合工具(教學序列型):Case 1→6 整體展示單一情境+分階段單變量參數掃描,逐步孤立一條規則嘅臨界條件(某選項嘅價值改變,係咪影響咗邊個係目前最高值)——教學設計手法,同 past paper「換情境唔換邏輯」屬唔同層次,值得留意正式考卷會唔會將呢六個 Case 壓縮成一條題目。 💡 跨來源確認(第2/3次):Case 2/Case 4 嘅兩步程序、新選項超越舊選項規則,同 Pearson Case Q1、MCQ Q9 呼應,已在上一輪記錄。

9. Section 1.2 Applications(續)Case 7–8 + Master Conclusions(P.14)

Case 7 — 買咗相機之後,發現拍出嚟嘅相好差(chosen option 嘅實際價值下跌,方向同 P.9 tripod 例子相反)。答案(原圖手寫字因拍攝角度部分模糊,核心邏輯清晰,唔逐字確認):相片差呢件事對「私人補習」呢個 highest-valued option forgone 冇任何影響,所以 OC remains unchanged;唯一改變咗嘅係被選選項(相機)自身嘅價值下跌。

💡 跨頁內部確認(mirror pair):呢個同 P.9 第1點(相機送tripod,value increase,OC不變)係同一個node嘅方向相反版本——被選選項自身價值下跌,一樣冇影響OC。呢個係「一問兩考、方向相反」呢個組合工具喺同一份校本教材入面自己內部嘅再一次確認(P.9 vs P.14),唔使等第二個chapter先撞到。

Case 8 — 假設今日冇任何其他活動,朋友送咗一張免費相機coupon,但要排隊2小時。OC = explicit cost(0,免費)+ implicit cost(0,因為冇其他活動,時間冇任何替代用途)= $0。

💡 新node:冇替代選項時 OC = 0——之前 Case 3(中獎免費相機)仍然有兩個替代用途(補習/精品店),implicit cost 唔係零。Case 8 進一步移除埋所有替代用途,證明 OC 唔係恆常正數——當根本冇嘢可以「畀你揀」放棄嗰陣,OC 就係零。呢個係「機會成本需要一個真實存在嘅替代選項」呢個前提條件嘅明確驗證。

Conclusion(Case 3–7):OC will change only if there is a change in the value of the highest-valued option forgone——呢句就係將前面Case 3-7全部觀察正式歸納做一句master rule,同P.10 mind map嘅結論完全一致。

Conclusion(Case 8):If there are no other options available,the cost will be zero,because there is nothing to give up(冇嘢要放棄)when making a choice。

True/false 判斷(a、b): a. "If digital camera becomes more expensive, the value of digital camera decreases." — Ans: 相機加價會增加攞到相機嘅(money)cost,唔會影響相機本身嘅value。Statement is incorrect。

💡 跨頁確認+延伸:呢個直接延伸 P.7「同價可以有唔同value」——而家反過來證明「唔同價都可以有同一個value」,confirm price 同 value 係兩個獨立維度,加價唔代表個人主觀評價跌低。

b. "If price of smartphone becomes more expensive, OC of getting digital camera decreases." — 邏輯鏈:smartphone加價 → 超出預算 → smartphone 變成 not affordable(同 P.7 notebook 機制一樣,被踢出 choice set)→ highest-valued option forgone 由 smartphone(2nd)降格做 iPad air(3rd,價值較低)→ OC decreases。Statement is correct。

💡 新組合工具(第三種「第三選項」變化機制):之前已知嘅第三選項變化只有兩種——(i)價值升跌但仍留喺choice set內(Case5/6、P.9/P.10);(ii)呢度新增第三種——價格升到超出預算,直接被踢出choice set,令forgone排名整條下移一級。呢個機制同(a)嘅「price≠value」相輔相成:(a)講被選選項加價唔影響OC,(b)講forgone選項加價可以影響OC——但唔係因為佢value變,而係因為佢被踢出局。兩題刻意對照設計,值得標記。

10. Section 1.2 Answering Technique — Joyce's Career Example(P.15,跨情境驗證)

情境轉為職業選擇(唔再係買嘢):Joyce preference order:1st=在香港嘅國際銀行工作,2nd=去新加坡銀行工作,3rd=留喺現職銀行。題目問嘅係揀最低preference(3rd,留任)嗰陣嘅OC會唔會必然不變——即forgone = 1st(國際銀行)。

Step 1(材料官方步驟):Find highest-valued option forgone = 1st option(國際銀行)。 Step 2:逐個情境判斷點樣影響highest-valued forgone。

a. 國際銀行工作量變得好重 → 呢個直接影響現有嘅highest-valued forgone(1st option)本身嘅value,可能下跌 → 留任嘅cost可能下跌 → 「必然不變」= No。 b. 新加坡前景轉差 → 影響嘅係2nd option(唔係現有highest-valued forgone)→ 冇效果 → 留任OC remains unchanged → 「必然不變」= Yes。 c. 新加坡出高薪 → 2nd option value上升,若新值超過1st option,就會換人做highest-valued forgone → 留任OC上升 → 但呢個係條件式(視乎升幅有冇超過1st option)→「必然不變」= No。

💡 跨情境確認(全單元最重要嘅一次驗證):呢個「Step 1搵highest-valued forgone,Step 2睇邊個情境影響緊佢」嘅官方答題框架,將之前全部喺「買相機」情境(Case1-8、P.9/P.10)驗證過嘅node,一字不變咁搬去職業選擇呢個完全唔同嘅情境,證明呢條規則唔係附屬於「購物」呢個表面情境,而係一個真正抽離咗context嘅通用經濟學機制。呢個亦係首次見到「被選選項係preference排名最低(3rd)」嘅設定(之前全部例子chosen option都係1st或者隨手指定),證明兩步程序唔受chosen option排名位置影響。 💡 結構對應P.10 mind map:a對應「highest-valued forgone本身變化」分支,b對應「第三選項變化但仍低於forgone,無影響」分支,c對應「第三選項變化可能超越forgone」分支——三個子題完整覆蓋咗mind map嘅三條分支,係一次刻意設計嘅總複習。

Next Step

1.2 內文已跑完(P.3-11+Applications P.12-13)。待下一批頁面:1.3 Goods 起。持續執行跨來源核對慣例:每題/每個 Case 完成後,即時對照 dse-econ-ch1-basic-concepts.md 已記錄嘅 node/relationship,標記confirm或新增。