题目内容：

用适当介词，连词或从句引导词填空

1.He held on _________the rope , and slipped down the cliff slowly.

2.You must devote your full attention________ what you are doing.

3.What is the theory based__________.

4.There is some doubt_______ he is the best man for the job.

5.No sooner had the boy spoken these words ________ the warden hit him on the head with the soup spoon.

6.The book is intended__________ children aged 5～7.

7.I was astonished ____________the news of his escape.

8.Lay these books ________________ you can find them easily.

9.She is acknowledged_______ _ the best tennis ­player in the world.

10.—Why do you look pale today?

—I was very concerned _______my mother’s illness. I stayed awake last night.