来自胡建国的问题
30.Ifhe__harder,hewillcatchupwithussoon.AstudyBstudiesCwillstudyDstudied.顺便说明理由..
30.Ifhe__harder,hewillcatchupwithussoon.
AstudyBstudiesCwillstudyDstudied
.顺便说明理由..


30.Ifhe__harder,hewillcatchupwithussoon.AstudyBstudiesCwillstudyDstudied.顺便说明理由..
30.Ifhe__harder,hewillcatchupwithussoon.
AstudyBstudiesCwillstudyDstudied
.顺便说明理由..
if条件从句的主句用将来时,从句用现在时表将来时,故选studies.