by the time you arrive this evening,_______ for two hours.a i will study bi willhave been studiedc i had studied d iwill have been studying
问题描述：
by the time you arrive this evening,_______ for two hours.a i will study bi willhave been studied
c i had studied d iwill have been studying
答
d iwill have been studying
表示将来的两个小时内一直在学习
答
选D，属于将来完成进行时，意思是“等你今晚到的时候，我将已经学了两个小时了（因为是进行时，所以届时仍在学）”
本题也可用排除法，首先by the time...表示一段时间，要用完成时，排除a，其次b中的study是被动语态，即“我被学习”，显然不对，c是过去完成时，时态不对（by the time后面跟的是一般现在时arrive，指示将来的时间，同when用法一样）。
答
选D，用将来完成进行时。
答
by the time you arrive this evening,_______ for two hours.
a I will study b.I will have been studied
c I had studied d I will have been studying
选项是d
答
答案选D
“by the time +将来时间”,用于将来完成时[will have done]或将来完成进行时[will have been doing],排除A,C.又由于B项是表示被动的,错误,故选D