Don’t promise anything _____ you are one hundred percent sure.

   A. if                            B. after                     C. in case                D. unless

The field research will take Joan and Paul about five months; it will be a long time _____ we meet them again.

A. after              B. before                        C. since                 D. when

____ has an interest in the lecture can go for a ticket from the office next to the gate of the

lecture room, _____ the lecture will be given.

A.No matter who, where      B.Whoever, where

C.Anyone, in which      D.Those who, in which

______ the Internet is of great help, I don’t think it’s a good idea to spend too much time on it.

       A. If               B. While                  C. Because           D. As

_____ the police thought he was the most likely one, they could not arrest him since they had no exact proof about it. 

       A. Although          B. As long as                C. If only                    D. As soon as

The strange man asked me to hand the letter to _____ I met in the police station, saying it was very important.

       A. whoever            B. whatever                  C. whichever                D. whomever

       Many experts believe that teachers’ development is _______ the key to better education lies. 

A. that                  B. what                 C. where               D. which

       Bad habits, _______ formed, are difficult, and sometimes impossible to shake off.

A. once                 B. before               C. until                 D. unless

The traffic in Shanghai will be blocked and people will come to blows _____ the government plans in advance.

A. as long as         B. unless               C. even if             D. since

He was disappointed ____ he had learned from books quite differed from his actual life.

A. what                 B. that                   C. which               D. how