一、补全句子。
同学们正在参观博物馆，边看展览边进行推理讨论。请根据语境用“must / may / might / could / can't”填空。（可重复使用）
1. The old jade piece be from a wealthy family. It looks very valuable.
2. It be a common thing. Its style is quite special.
3. There is some ash on the object. It come from an old fire long ago.
4. The workers are trying hard to repair this ancient bowl, but it be easy.
5. Some people believe ancient people traded in jade, and it have brought great wealth at that time.
6. Archaeologists find more jade objects in the deeper part of the tomb later.

1. must
2. can't
3. may / might / could
4. can't
5. must
6. may / might / could

【分析】本题考查情态动词表推测的用法，需结合语境判断推测的肯定程度：must表有把握的肯定推测，can't表有把握的否定推测，may/might/could表不确定的可能性推测。1. 玉器看起来贵重，有充分理由肯定其来自富裕家庭，用must；2. 风格特别，不可能是普通物品，用can't；3. 物体有灰，推测可能来自旧火，不确定，可用may/might/could；4. 努力修复但（修复）不可能容易，否定推测用can't；5. 古人用玉交易，肯定带来财富，用must；6. 之后可能找到更多玉器，不确定，可用may/might/could。
【解析】1. 句中提到玉器“looks very valuable”，有充分依据进行肯定推测，故用must；2. 句中“style is quite special”说明其不可能是普通物品，表有把握的否定推测，故用can't；3. 物体上有灰，推测可能来自很久以前的火，属于不确定的可能性推测，may、might、could均可使用；4. 前半句说工人努力修复古碗，转折后表否定推测，即（修复）不可能容易，故用can't；5. 古人用玉交易，有依据肯定玉在当时带来财富，表有把握的肯定推测，故用must；6. 对未来墓中是否有更多玉器进行可能性推测，属于不确定推测，may、might、could均可使用。
【答案】1. must；2. can't；3. may / might / could；4. can't；5. must；6. may / might / could
【知识点】情态动词表推测
【点评】本题围绕情态动词表推测的核心用法，结合具体语境判断推测的类型（肯定/否定、确定程度），属于基础语法题，只要掌握不同情态动词的推测用法即可正确作答。
【难度系数】0.6