83．Could you give us some__________on how to learn English well?

82．Could you please clean your room? It’s too___________!

81．How do you make a banana ____________／milk／shake?

50．(　 　)It’s windy．You’d better _______ the windows open when you go out．

　　 A．not leave　　 　　　　　 B．don’t 1eave　 　　　　　 C．not to leave 　　　　　 D．not leaving

49．( 　　)一Who knows _________we can get to the airport?

　 　　　一I’m afraid it ______ on the traffic．

　　 A．how far，looks 　　 B．how often，depends C．how long，looks D．how soon，depends