28. The pen I______ I _______ is on my desk, right under my nose.
A. think, lost
B. thought, had lost
C. think, had lost
D. thought, have lost
答：B。我本(原)以为我丢了的那支钢笔就在我的书桌上。不难看出应选B项。“本以为”应用过去时thought，“丢”这一动作应表示在过去的过去，应用过去完成时。
29. —Can I join your club, Dad?
—You can when you _______ a bit older.
A. get B. will get
C. are getting D. will have get
答：A。when此处可视为一种条件状语，相当于小will不能用于if引导的条件状语从句中表示将来，应用现在时代替将来时。如：When there is no gravity, our feet will no longer stay on the ground.如果没有引力存在的话，我们的脚就不能在地面上停留。
30. —Do you like the material?
—Yes, it____________ very soft.
A. is feeling B. felt
C. feels D. is felt
答：C。feel为系动词，不能用进行式，也不用被动语态．
31. I don’t really work here, I____________ until the new secretary arrives.
A. just help out
B. have just helped out
C. am just helping out
D. will just help out
答；C。指现阶段正在进行的动作。从原题 I don’t really work here “实际上，我不在这工作”这一信息句可判断出．这句话的真正意思是“我正在这帮忙(这是暂时的)。”
32. —We haven’t heard from Jane for a long time.
—What do you suppose _________ to her?
A. was happening
B. to happen
C. has happened
D. having happened
答：C。第一句是信息句，所用的时态是完成时，答语中的时态也应用现在完成时。do you suppose 是插入语。
33. The volleyball match will be put off if it _______.
A. will rain B. rains
C. rained D. is raining
答：B。主句用将来时，从句用一般现在时代替将来时。另外will不能用在if引导的条件状语从句中表示将来，但可用在if引导的条件从句中表示愿望。如：I you will havea try, 1 will giveyou a chance. 如果你愿意试一下，我就给你一次机会。