25. I would appreciate___________ back this afternoon.
A. you to call B. you call C. your calling D. you’re calling 答：C。 appreciate欣赏，感激，后接 doing .... 26. There’re so many kinds of tape-recorders on sale that I can’t make up my mind_______to buy. A. what B. which C. how D. where 答：B。which to buyy该买哪一个，其他与句童不符． 27. _______ a reply, he decided to write again. A. Not receiving B. Receiving not C. Not having received D. Having not received 答：C。分词的否定式not+-ing，此处应用完成式。 28. “Can’t you read?” Mary said___________ to the notice. A. angrily pointing B. and point angrily C. angrily pointed D. and angrily pointing 答：A。修饰动词sadi应用副词angrily, pomnng为分词做伴随状语。 29. How about the two of us ______ a walk down the garden? A. to take B. take C. taking D. to be taking 答：C．about介词后应接动名词做宾语。 30. The computer center, ___________ last year, is very popular among the students in this school. A. open B. opening C. having opened D. opened 答：D．opened为过去分词做定语，相当于非限制性的定语从句which was opened last year, ....。 31. Charles Babbage is generally considered ________ the first computer. A. to invent B. inventing C. to have invented D. having invented 答：C．不定式的完成式表示不定式本身的动作发生在谓语动词之前。如：We seem to have met each other before.我们似乎以前见过面。