—Have you got any books on English grammar? I’d like to borrow       ．

—Yes, here you are．But you must return it by Friday．

A．it

B．one

C．some

D．any

反应堆生产的核素常是()

A．中子缺乏

B．存在时间短

C．中子过剩

D．价格特别昂贵

E．以上都不对