7、us,healwaysprefers________abicycle.A.ride;torideB.ride;rideC.riding;rideD.toride;riding18.Thewarmade________impossibleforEinsteintogoonwithhisresearch.A.thisB.himC.thatD.it19.Tom______beathomenow,becausehewasseenplayingbasketballinthestadiumjustnow. A. can’t B.needn’t