高中英语单选问题1）Return to the test questions that you ____answer i

高中英语单选问题
1）Return to the test questions that you ____answer immediately and see if you can answer them now.
A,weren't able to B,aren't able to C hadn't been able to D, haven't able to
2)China has also made important contribution to helping underdeveloped nations,thus__praise from the international community.
Awins B,to win C,winning D,won
3)The minister expressed his gratitude to Dell Company and Mr Dell himself for their attention__to China's education.
A,to pay B,paying C,paid D,having paid
4)There is a possibility that these hens could be frightened and lay fewer eggs__a sudden loud noise.
Awould there be B,there was ,C,should there beD,there having been
要原因的,谢谢