Dear Peter,
Thanks very much on inviting me to your birthday 86. ________
party on Sunday. I'd like very much come but 87. ________
I had an examination on Monday morning. It is 88. ________
a very important exam but I can't afford to 89. ________
fail it. I'll spend all the whole weekend reading 90. ________
and prepare for it. So I'm really sorry that 91. ________
I won't be able to come in this time. Hope you 92. ________
can understand. I'll take this chance to wish 93. ________
you wonderful time on your birthday. Happy 94. ________
birthday, Peter, and many happy return of the day! 95. ________
Yours,
Li Ming
86.on→for
87.much后加to
88.had→will have
89.but→and/so
90.划掉all
91. prepare→preparing
92.划掉in
93.√
94.you后加a
95. return→returns
86.on→for考查介词用法。Thanks后接介词for表示为什么而感谢，后接动名词作宾语。
87.much后加to考查动词不定式的用法。I'd like to do sth.的意思是“愿意做什么”。
88.had→will have考查动词时态。根据上下文可以确定此句的谓语动词是一般将来时。
89.but→and/so考查连词的用法。根据句意可知，此句是并列关系，而不是转折关系。改为and，表示“并且”；改为so，表示“因此”。
90.划掉all考查代词的用法。all一般不和whole连用。这句话的意思是“我将花费一周的时间阅读和准备(考试)。”
91. prepare→preparing考查非谓语动词的用法。preparing和reading是并列关系，构成spend some time(in) doing sth.句型。
92.划掉in考查介词的用法。this time的意思是“这次”，前面不用介词。
93.√
94.you后加a考查冠词的基本用法。time前有形容词时常加不定冠词。
95. return→returns考查名词的数。return在该句中是名词，根据前面的many可以确定它是复数名词。