联招英语·完形填空：情态动词与推测语气设空

题目性质：自编仿真题——题目、材料、选项、数据与情境均为按课程标准与联招常见考点独立编写的原创仿真题，非真题原文，未取自任何题库、教辅或试卷；解析与采分点为教研整理，非官方评分标准。

一、考点定位与做题顺序

遇到四个情态动词都能填，先别比词义，比两件事：一是确定性（must 几乎断定 ＞ may/might 可能 ＞ can not 否定性断定），二是时间指向（对过去的推测用「情态 + have done」，对现在用「情态 + 动词原形」）。再把第三类分开：should have done 不是推测，是「本该做却没做」的遗憾/责备；would rather 是偏好，不表推测。

三步判断：看语境给了多少证据（有硬线索才配 must）→ 看动作发生在何时（过去用 have done）→ 看句子要的是推测、义务还是偏好。下面短文为自编示意文本，人物、社团、时间与数据均虚构。

二、逐题精讲

题1

题1 五空完形（每空四选一）

自编短文：When the archive box came back, its label was soaked and the ribbon gone. Ms. Ren said the box (1) ___ have been left near the open window during the storm — the sill was still wet, and no one else had a key. Yet Li was less certain: the caretaker (2) ___ have moved it to the corridor earlier, so the damp (3) ___ not have come from the window at all. What puzzled us was the register: we (4) ___ have signed it out on Friday, but the line was blank. Ms. Ren smiled: "I (5) ___ rather check the log than guess."

(1) A. must　B. may　C. should　D. would
(2) A. must　B. might　C. can　D. need
(3) A. must　B. should　C. may　D. would
(4) A. must　B. should　C. might　D. could
(5) A. had　B. would　C. could　D. must

解析

(2) B. might。「Li was less certain」明说不确定性下降，且是另一种可能的解释，用 might have moved。A must 与 less certain 冲突；C can have moved 一般不用于肯定句表过去推测（多用于疑问/否定）；D need have moved 表「本不必」，不搭配。

(3) C. may。 承接上一句的另一解释，「潮气可能根本不是从窗子来的」：may not have come 表「可能没……」。关键辨析：must not have done 在标准用法中不作「一定没……」的推测（否定性断定要用 can not / could not have done），故 A 不可选；B should not have come 是「本不该来却来了」的责备；D would not 不表推测。

(4) B. should。「登记册上那一行是空的」＋「What puzzled us」提示本该做而未做的遗憾 → should have signed it out（我们本该在周五登记借出）。A must have signed 与「line was blank」矛盾；C/D 只表可能性，写不出「本该」的落差感。

(5) B. would。 固定搭配 would rather do A than do B（宁愿 A 而不愿 B），后接动词原形 check / guess，正是原句形式。A had rather 非标准搭配（had better 才是另一结构）；C could rather、D must rather 均不成立。

答案　(1) A must　(2) B might　(3) C may　(4) B should　(5) B would

采分点　每空 1 分；另计：(1) 指出两条硬线索支撑 must 1 分；(2) 由 less certain 定 might 1 分；(3) 说明否定性断定须用 can/could not have done、must not have done 不表该义 1 分；(4) 区分 should have done 的「本该未做」与推测 1 分；(5) would rather…than 后接原形 1 分。

易错点　见「不确定」就一律填 may，漏看 (1) 的排他证据；把 must not have done 当成「一定没」；把 should have done 当推测；把 would rather 与 had better / would like 混用；忽略 have done 与动词原形分别对应过去与现在。

题2

题2 辨形改错与语气改写

(1) 改正下列三句并说明理由：
a) The sill was dry and the box was damp; the rain must not have reached it.
b) We should have signed the register out on Friday — and in fact the line shows we did.
c) I would rather to check the log than to guess.
(2) 把「Someone left the box near the window.」改写为两句：一句表对过去的几乎断定，一句表对过去的低确定推测；并说明两句各自需要什么样的上下文证据才站得住。

解析

(2) 几乎断定：The box must have been left near the window. 需要排他性硬证据：如窗台仍湿、只有一人有钥匙、监控或登记显示无人移过——即「其他解释都被排除」。
低确定推测：The box may / might have been left near the window. 只需一条相容线索即可（如窗开着、有人习惯把箱子放窗边），但不能排除其他可能；若上下文出现「别处也可能」，就必须降档到 may/might，不能硬用 must。
两句都用「情态 + have + 过去分词」，因为动作发生在过去；差别全在上下文给出的证据强度，不在动词形式。

答案　(1) a) must not→can/could not have reached；b) should have 与「in fact we did」矛盾，改为事实陈述或补 but the line was blank；c) 去掉两个 to，would rather check… than guess。(2) must have been left（需排他硬证据）／may·might have been left（只需相容线索且承认他解）。

采分点　三句改错各 2 分（改对 1 分＋理由 1 分）；must not 与 can not 的分工 1 分；should have 的「实际未做」预设 1 分；would rather 后原形 1 分；(2) 两句各 1 分、证据强度说明各 1 分。

易错点　把 must not have done 当「一定没」；在 b) 里只改时态不改预设，仍留矛盾；把 would rather 与 had better / prefer to 混为一谈；改写题两句都用 must，忽略证据强度差异；忘记对过去推测一律加 have done。

三、规律小结与对照表

这类空三步收口：先数证据，再定时间，最后分清是推测、义务还是偏好。证据排他才配 must，只有一条相容线索就用 may/might；动作在过去一律「情态 + have done」；见到 should have done 先检查「实际是不是没做」，见到 would rather 先去掉多余的 to。特别记住一条：「一定没发生」是 can/could not have done，不是 must not have done。本文短文、人物与数据均为原创自编示意内容。

四、自测清单

• □ 先数上下文给了几条证据，排他才用 must；
• □ 对过去的推测一律「情态 + have + 过去分词」；
• □ 否定性断定用 can/could not have done，不用 must not；
• □ should have done 预设「实际未做」，与「已做」并用即矛盾；
• □ would rather do A than do B，两处都用原形、不带 to；
• □ 四个选项语法都通时，比确定性与时间指向，不比词义轻重。