Don’t leave the water       while you brush your teeth.

   A. run      B .running     C. being run   D. to run

 —May I tell this to my close friend?

—No, you       . Never let anybody else know about it.

   A. needn’t      B. shouldn’t      C. mustn’t         D. can’t

 The world is changing fast. I strongly believe that one will easily fall behind         he keeps on learning.

   A. unless        B. if           C. when       D. as

 His speech at the meeting was really wonderful, and it could never be any         .

A. best          B. better        C. worse     D. worst

 All the          indicate that he has been deeply involved in the crime.

A. evidence    B. fact    C. factors     D. cause

 —Are you free after school?

—Sorry: I’ve planned to treat a friend of mine to dinner        for his help.

A. in terms      B. in honor    C. in turn     D. in return

 —Alice, you look puzzled. Have you understood it?

—Yes, I         another problem just now.

A. have thought of      B. am thinking of

C. had thought of       D. was thinking of

 Whether ways will be found to stop pollution or not is just          worries the public.

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

 Travelers         that they should bring their ID cards with them.

A. have reminded      B. are reminded

C. were reminding     D. had been reminded

 Shanghai has hosted        2010 world Expo. The world Expo has        long history but it has never been held in Asia.

   A. ——；a     B. the ;  a      C. the ;  the     D. / ;   /