1. Only when ________ possible to settle the problem.

A. does the chief editor come will it be        B. the chief editor comes will it be

C. has the chief editor come it will be          D. the chief editor comes it will be

2. The tourists didn’t stop to rest at each station because it _______, them down.

A. had slowed                                           B. would slow       

C. should have slowed                               D. would have slowed

3. ---Did you blame him for his mistakes?

  ---Yes, but I’d rather _______it.

A. not do               B. not to do                  C. have not done                  D. not have done