You can’t imagine the hard time he had ______ the horse in.
| A.holding | B.to hold | C.held | D.hold | 
27.—Do you know when Phil's coming?
  —He ______ 4: 00.
| A.says | B.has said | C.had said | D.Said | 
26.Even if there is no scientific proof yet ______ secondhand smoke causes cancer, there is no reason why nonsmokers should be forced to take this risk.
| A.which | B.that | C.when | D.Where | 
25.With so little time ______ on math, it is all too easy for children to ignore practicing mathematics, which is a kind of language.
| A.spent | B.being spent | C.to spend | D.was spent | 
24.One recent prediction is that within the next 50 years, it ______ possible to link the human brain directly with a computer.
| A.is | B.will be | C.would be | D.Was | 
23.—I have ______ high temperature and ______ sore throat.
  —Well, you may have the flu.
| A.a; a | B.the; the | C.the; a | D.a; the |