It is strange that the small boy _________ work out such a difficult exercise, which is even hard to settle for adults.
A. should B. might C. could D. would
His wife has left him, but he behaved _______ nothing had happened.
A. even though B. as soon as C. as though D. as long as
Clearly, in a system _________ every decision is made on the basis of tradition alone, it may be difficult to achieve progress.
A. that B. when C. where D. which
Suddenly it _________ to me that I should report the accident to the police.
A. happened B. struck C. occurred D. hit
The following chapters provide step-by-step instructions for practical _______ of genetic (基因)engineering to agriculture.
A. applications B. organization C. expression D. attention
What a moving _____to see so many people offer help to these in danger!
A. sight B. scene C. view D. scenery
