題目性質：自編仿真題——題目、材料、選項、數據與情境均為按課程標準與聯招常見考點獨立編寫的原創仿真題，非真題原文，未取自任何題庫、教輔或試卷；解析與採分點為教研整理，非官方評分標準。
一、考點定位與做題順序
條件設空先分兩類：真實條件（可能發生，主句用陳述語氣）與虛擬條件（與事實相反，時態要「退一格」）。真實條件裡幾個連詞各有分工：
if（如果）、unless（除非＝if … not，但只用於「若非此條件則不成立」，別硬套到所有否定句）、provided (that) / providing（前提是，書面、帶約定口吻）、as long as（只要，強調持續條件）、in case（以防、萬一，不是「如果」）、otherwise（否則，副詞，常接 or 的語義）、but for / without（要不是，含蓄條件，主句多用 would have done）。
虛擬語氣兩套基本式：與現在相反 If + 過去式, … would + 動詞原形；與過去相反 If + had done, … would have done。做題四步：判真實還是虛擬 → 找條件連詞的語義分工 → 核主從句時態搭配 → 回讀看是否「以防/否則/前提」。下面短文為自編示意文本。
二、逐題精講
題1
題1 八空完形（每空四選一）
自編短文：The community greenhouse would open in April (1) ____ the roof panels arrived on time. Ms Iver said we could use the side beds (2) ____ we kept the paths clear. She also asked us to stack the spare glass (3) ____ a sudden frost damaged the young plants. (4) ____ the delivery had come a week earlier, we (5) ____ the first sowing before the cold spell; in fact it came late, so we had to wait. (6) ____ the delay, every seedling would have been ready by now. (7) ____ the volunteers had labelled each tray, the records would be in confusion now. She had also asked for a paper log; (8) ____, the sowing dates would have been lost.
(1) A. unless B. provided C. in case D. otherwise
(2) A. as long as B. in case C. unless D. but for
(3) A. if B. in case C. provided D. as long as
(4) A. If B. Unless C. In case D. Provided
(5) A. would finish B. would have finished C. finished D. had finished
(6) A. But for B. In case C. As long as D. Provided
(7) A. If B. Unless C. In case D. But for
(8) A. otherwise B. unless C. provided D. in case
解析
(1) B provided：「屋頂板按時到」是四月開放的前提，書面約定口吻，正是 provided (that)。unless 會變成「除非板子按時到，否則四月開放」——邏輯反了；in case 是「以防」，不接前提；otherwise 是副詞，不能引導從句。(2) A as long as：「只要把通道保持暢通，就可以用側畦」，強調持續條件。unless 會把許可變成否定條件；but for 後接名詞不作連詞；in case 語義不通。
(3) B in case：「把備用玻璃疊好，以防突降霜凍傷了幼苗」。這是本題最硬的信號：in case 表預防，不等於「如果」；選 A if 就成了「如果霜凍來了就疊玻璃」，動作順序與目的全反。
(4) A If (5) B would have finished：後句「in fact it came late, so we had to wait」明示與過去事實相反，故用與過去相反的虛擬：If the delivery had come a week earlier, we would have finished the first sowing…。從句 had come 已給出，主句必須 would have + 過去分詞；A 是現在/將來虛擬、C 是陳述過去、D 是從句形式，都不配。
(6) A But for：But for the delay, every seedling would have been ready by now＝「要不是延誤，苗早就齊了」。but for + 名詞 是含蓄條件，主句 would have been 正好配套；三個連詞選項都不能接名詞短語。
(7) B Unless：Unless the volunteers had labelled each tray, the records would be in confusion now＝「若不是志願者給每個托盤貼了標籤，記錄現在就該亂了」。這裡 unless 引導與過去事實相反的否定條件（＝if they had not labelled…），與後文 would be … now 構成錯綜時間虛擬（過去條件 → 現在結果）。選 A If 會把已發生的事說成未發生，與「記錄沒亂」的事實衝突；C、D 句法不合。
(8) A otherwise：We kept a paper log otherwise, just as she had asked 中的 otherwise 作副詞，承接前文「照她要求另留一份紙質記錄」。此處更自然的讀法是「我們另外/照舊保留了紙質記錄」，與 or / otherwise 的「否則、另作安排」語義相承；三個連詞選項後面都沒有從句，語法不成立。回讀全篇：前提 → 持續條件 → 預防 → 過去虛擬 → 含蓄條件 → 錯綜虛擬 → 收束，八空的條件類型互不重複。
答案 (1) B provided (2) A as long as (3) B in case (4) A If (5) B would have finished (6) A But for (7) B Unless (8) A otherwise
採分點 八空各 1 分；(1) 說明 provided 表書面前提、unless 會邏輯反 1 分；(3) 說明 in case 表預防而非「如果」1 分；(4)(5) 判「與過去相反」並寫出 had done / would have done 搭配 2 分；(6) but for + 名詞為含蓄條件 1 分；(7) 說明錯綜時間虛擬（過去條件→現在結果）1 分；全篇條件類型梳理 1 分。
易錯點 把 unless 一律當成 if not 硬套到 (1)；把 in case 當「如果」選 (3)；(5) 看到 had come 卻選 would finish（漏過去虛擬）；(6) 用 In case 接名詞；(7) 選 If 把已發生的事實說成假設；(8) 選連詞卻沒有從句；忽略 in fact it came late 這一「與過去相反」的明示信號。
題2
題2 虛擬語氣改錯與三組近義辨析
(1) 改正下列三句（每句一處）：① If the delivery would have come earlier, we would have finished the sowing. ② If I would have known about the frost, I had covered the trays. ③ In case of the delay, every seedling would have been ready by now.
(2) 辨析三組：a) unless / if…not；b) in case / if；c) provided / as long as，各寫一句能顯出差別的自編例句。
解析
(1) ① If the delivery had come earlier, we would have finished the sowing.（與過去相反的虛擬，if 從句用 had done，不用 would have；would have 只出現在主句）。② If I had known about the frost, I would have covered the trays.（從句 had known、主句 would have covered，兩處都要退一格；原句把 would have 放錯位置、主句又用了 had covered）。③ But for the delay, every seedling would have been ready by now.（in case of 表「萬一發生」，是預防，不表「要不是」；含蓄條件須用 but for + 名詞 或 without）。規則一句話：if 從句不帶 would；與過去相反用 had done ↔ would have done；「要不是」用 but for，不用 in case of。
(2) a) unless 是「除非/若非」，含「唯一例外」口吻，if…not 只是一般否定條件：Unless the panels arrive today, we cannot open in April — if they do not arrive, we shall simply move the sowing table, not cancel the plan.
b) in case 表「以防、萬一」、動作發生在前；if 表「如果」、動作發生在條件成立之後：Stack the spare glass in case a frost comes; if a frost does come, cover the trays at once.
c) provided (that) 偏書面、強調「約定的前提」；as long as 強調「持續保持」：Provided the roof is repaired, we may use the greenhouse; as long as the paths stay clear, the side beds remain open.
三句都須在同一句裡讓兩個結構各自顯義，只列中文對應詞不給滿分。
答案 (1) ① had come；② had known / would have covered；③ But for the delay。(2) 三組例句見上。
採分點 三句改錯各 1 分；寫出「if 從句不帶 would / had done↔would have done / but for 表要不是」三條規則各 1 分；三組辨析每組語義 1 分、例句顯差別 1 分；例句時態搭配正確 1 分。
易錯點 把 ① 改成 If…would come（現在虛擬）卻沒對上主句 would have；② 只改一處漏另一處；③ 改成 In case the delay…（仍表預防）；辨析時把 unless 與 if…not 說成「完全一樣、隨時可換」；in case 例句裡把預防動作寫在條件之後。
三、規律小結與對照表
| 結構 | 語義/時態 | 自編例 | 把關點 |
|---|---|---|---|
| provided (that) | 書面前提 | …opened provided the panels arrived | ≠ unless |
| as long as | 只要（持續） | as long as we kept the paths clear | 強調持續 |
| in case | 以防、萬一 | in case a frost damaged… | 動作在前 |
| otherwise | 否則/另作安排 | kept a paper log otherwise | 副詞，不接從句 |
| 與過去相反 | had done ↔ would have done | had come → would have finished | if 從句不帶 would |
| 含蓄條件 | but for / without + 名詞 | But for the delay, …would have been | 不用 in case of |
| 錯綜虛擬 | 過去條件→現在結果 | Unless…had labelled, …would be now | 時間不一致 |
| unless | 除非/若非（唯一例外） | Unless they had labelled… | ≠ 所有 if not |
條件設空的穩解，是先判真實還是虛擬，再給連詞定分工：provided 是約定的前提、as long as 是持續保持、in case 是預防且動作在前、but for 後接名詞表「要不是」、otherwise 是副詞不接從句。虛擬語氣記住「if 從句不帶 would；與過去相反 had done ↔ would have done」，再留意「過去條件→現在結果」的錯綜時間。回讀一遍看前後事實是否對得上，八空就不難。本篇短文、人物、機構與選項均為自編示意，不代表真實事件。
四、自測清單
- □ 先判真實條件還是與事實相反的虛擬；
- □ 找 in fact / in fact it came late 這類明示事實的句子定時態；
- □ if 從句絕不帶 would；與過去相反用 had done ↔ would have done；
- □ in case 表「以防」、動作在前，不與 if 混；
- □ but for / without 後接名詞，是含蓄條件，不用 in case of；
- □ provided（書面前提）與 as long as（持續保持）分開用；
- □ otherwise 是副詞，後面不接從句；最後回讀核對事實與結果是否一致。
