用所给单词的适当形式完成句子。

A) extreme

1. I am ______ sorry to have troubled you so much.

2. I am grateful to her for always showing ______ gentleness and kindness to me.

B) suffer

3. He felt pity for a man who had ______ so much.

4. It is hardly possible to forget the ______ caused by the war.

C) express

5. Young children often have difficulty in ______ themselves.

6. Learning more words and ______ plays an important part in language studies.

D) frighten

7. She will be ______ to death when she sees the way you drive.

8. It is ______ to think how easily children can be hurt.

9. Hearing the terrible noise, the girl had a ______ look on her face.

E) congratulate

10. As soon as he met me the next day, he ______ me warmly on passing the driving test.

11. I would like to express my ______ to all of you for such a wonderful performance in the exam.

12. "______ to all of you on your great success!"our coach said the moment he saw us.

F) sincere

13. Finally, I'd like to express my ______ gratitude for your help in this matter.

14. At the end of the letter, we often use the expression "Yours ______".