20．Tell John not to leave the house unless he　　　 that the lights　　　 .

A．will make sure，turn off　　　　　 B．makes sure，are turned off

C．will make sure，will turn off　　　 D．makes sure，will be turned off

19．Mrs．Brown is so　　　 about her housework that few servants Want to work for her．

A．skillful　　 B．neat　 C．particular　 D．special

18．After you have used the dictionary，please just put it back　　　 it belongs．

　　 A．to whom　　 B．to which　　 C．what　　 　D．where

17.We were badly treated in the hospital.

　 Don’t worry.The president has promised to ______ your complaint at once.

　　 A．look up　 B．look into　 C．look back on　 D．look forward to

16．It is usually not quite cold in this area in March，but sometimes temperature ______ low.

　　 A．should　　 B．must　　 C．can　　　 D．shall