Mr. Brown is 70 this year. Although he is very old, ____ he works very hard. 

---How long have you known the doctor ?  ---_________he helped me three years ago.

_______ the boy was walking down the street, the UFO landed.

 In a position like this, one can ________  stand up _______ lie down . So it is very uncomfortable.

__________Project Hope , thousands of children have better lives.