Period Six Grammar & Writing
Ⅰ.用所给词的适当形式填空
1．China sent up Shenzhou Ⅸ manned spaceship into space successfully，which shows science and technology have been developing (develop) rapidly in China.
2．Years ago we didn’t know this，but recent science has shown (show) that people who don’t sleep well get ill easily.
3．The two friends have been chatting (chat) on the Internet for three hours，and they will go on till next morning.
4．—How long have you been working (work) in the factory?
—Since 1990.
