1 . Kevin’s little brother is smart and he worked out this math problem by ________. (he)

2 . The purpose (目的) of the activity is to help children live alone.
The activity ________ ________ help children live ________ ________.

3 . 在她六岁的时候她就能独自走着去上学了。
She could walk to school ________ at the age of six.

4 . —Who teaches _________ English, Xiaoming?
—Nobody. I learn it by _________.

A．you; myself

B．you; me

C．your; myself

D．your; me

5 . If your friend tells you a secret, you should keep it ________.

A．by yourself

B．to yourself

C．for yourself

6 . by himself, enough, find out, he, to, clever, isn’t, the truth (连词成句)
____________________________________________.

7 . Although peter is five years old, he is learning to make the bed by _______. (he)

8 . The old man lives all alone but he never feels lonely.

A．being himself

B．for himself

C．by himself

9 . Though she was busy, she kept on learning English by ________.

10 . The children learned to cook a meal by __________. (they)