-Look at these tracks. It be a wolf. -It needn't be. It be a fox. A. must ; coul
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—Look at these tracks. It __________ be a wolf.
—It needn't be. It _______be a fox.
A. must ; could B. may ; might
C. need ; must D. could ; need
试题答案
A
解析:
第一空的答案要根据答语来判断。“needn't'’的出现表明第一空为“must”。后一空表猜测，可以用could。