Ｉdon’t think Linda could have done such a stupid thing last night，_________?
| A．do I | B．didn’t she | C． did she | D．don’t I |
16．—Where is Lily, Lucy? I cannot find her anywhere.
—She_________have been off long. I saw her clean the window just now.
| A．shouldn’t | B．can’t | C．mustn’t | D．needn’t |
15．While he has failed again and again, he never gives up in order to________his dream.
| A．achieve | B．awake | C．admit | D．Control |
14．This doubt had been in my mind for some time, but the research still went on____some reasons.
| A．to | B．about | C．for | D．In |
13．Not until I was a senior student_________the importance of English.
| A．I have realized | B．did I realize | C．have I realized | D．I realized |
12．There is__________in what you say; I will take your advice.
| A．everything | B．anything | C．something | D．Nothing |