用所给词的适当形式填空，每空一词。

1.  Last summer my friends and I went ______ (camp) in the forest. It was exciting.

2.  Her mother went out a moment ago.  She is ______ (babysit) her little sister.

3.  Just now I ______ (hear) him play the violin.

4.  —What are Liu Ying and her classmates doing for vacation?

    —They are going______ (hike) in the mountains.

5.  I am______ (plan) to have a relaxing vacation.

6.  The company (公司)______ (send) some engineers abroad last year.

7.  —What are they doing for vacation?

    —They are______ (relax) at home.