A. build B. build into C. build on D. build up
A. one B. that C. ones D. those
A. It was B. That was C. Although D. When
A. keep B. have C. last D. go
A. burst B. went C. fell D. exploded
A. up B. up to C. on D. in
A. came across B. came about C. came after D. came at
A. in B. at C. from D. with
A. playing B. play C. played D. to play
A. has ecome infected B. has become infecting C. had become infected D. had become infecting
A. if;when B. if; as long as C. whether; as long as D. whether; since
A. must not have B. couldn’t have C. may not have D. can’t have
A. in... to make B. about... to make C. in... making D. about... making