一、用括号中所给单词的适当形式填空。
1. Please (lock) the door so that we can enter the room.
2. The little garden was (hide) behind the tall trees.
3. He spoke (secret) about his plan to surprise everyone.
4. We should (force) ourselves to finish homework on time.
5. She acted (selfish) by taking all the snacks for herself.
6. After much thought, we (prove) that the answer was correct.
7. The (read) found the book so interesting that he read it twice.
8. The (alien) appearance in the science fiction movie is quite strange.

1. unlock
2. hidden
3. secretly
4. force
5. selfishly
6. proved
7. reader
8. alien's

二、从方框中选择合适的单词补全句子。
donate value organization teamwork effort
1. is very important in every rescue work.
2. The aims to provide aid for the elderly.
3. Let's some books to the children in poor areas.
4. The success of the activity depends on everyone's .
5. The of helping others can't be measured by money.
life-saving active visitor sign practical
6. He is an volunteer and takes part in many activities.
7. We need to up if we want to join the volunteer group.
8. It's important to learn some skills in daily life.
9. It's a way to clean up the park with our classmates.
10. As a , you can ask the volunteer for directions in the museum.

1. Teamwork
2. organization
3. donate
4. effort
5. value
6. active
7. sign
8. practical
9. life-saving
10. visitor