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问题 选择题

下列有关细胞和化合物的叙述中，不正确的是[ ]

A．质粒中含有核糖

B．ATP的化学元素包括C、H、O、N、P

C．RNA聚合酶具有识别作用

D．细菌中含有核糖体、DNA和RNA

答案

答案：A

选择题

— May! How is your plan? I heard you started it last Sunday.

— Oh! I _____ for it, but I haven't decided where to start it. [      ]

A. have prepared

B. had prepared

C. have been preparing

D. was preparing

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单项选择题

河道整治建筑物主要包括（）、垛和护岸。

A.丁坝

B.挑流坝

C.砌石坝

D.丁扣坝
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