Unit 4 An old man tried to move the mountain.
I.单项选择。
1．I _______ my homework as soon as I got home last night．
A．do B．did C．will do D．am doing
2．Miss Gao asked a question，but it was ______ that nobody could answer it．
A．very difficult B．too difficult C．difficult enough D．so difficult
3．— Smoking is bad for your health．
— You’re right．I decide to ______．
A．take it down B．find it out C．turn it off D．give it up
4．Cao Wenxuan’s new book has just _______．Let’s go and buy one．
A．come over B．come down C．come on D．come out
