A.know | B.have known | C.knew | D.have been known |
A.spend | B.had spent | C.have spent | D.will spend |
A.are operating | B.were operating | C.operate | D.operated |
A.is | B.will be | C.was | D.has been |
A.do | B.have to | C.have to speak | D.must to |
A.will build | B.will be built | C.would build | D.would be built |
© 2017-2019 超级试练试题库,All Rights Reserved.