10．The old scientist was awarded a gold medal for what he ________(do)for the development of modern science since the mid-twentieth century．

9．I don't think Aunt Wu would mind ________(take) care of our children while we're away．

8．The engineer ________(search) for some information on the Internet in the study while his wife was cooking in the kitchen．

7．In the old days the working people in our country ________(look)down on．

6．Sometimes clouds are so thick that they do not let much sunshine ________(come)through．

5．The little girl will give the flowers to the hero when he ________(appear)．

4．Shortly after he knew some English，he went on ________(teach)himself French．

3．You ________(not know)what the pear tastes like if you don't eat it．

2．Usually the thunder ________(hear)after the lightning．

1．No country ________(make)such great progress as China in the past thirty years．