87. Charity groups organized various activities to ________（为地震幸存者筹款）.
88. Linda_______（不可能收到我的电子邮件）；otherwise, she would have replied.
89. It's my mother________(一直在鼓励我不要灰心)when I have difficulties in my studies.
90. The publishing house has to ________（考虑这部小说的受欢迎程度）.
91. It is absolutely wrong to _________(仅仅以金钱来定义幸福).

答案及解析：

87. Charity groups organized various activities to raise money for the survivors of the earthquake. (为地震幸存者筹款)
【解析】本题考察动词raise的用法。raise money 表示筹款。同时考生要注意survivor （幸存者）的拼写。

88. Linda couldn’t have received my e-mail (不可能收到我的电子邮件), otherwise, she could have replied.
【解析】本题考察混合型虚拟语气。otherwise提示我们句子后半句是与过去事实相反（事实是Linda没有回复），因此用could+have+过去分词。句子前半句是在陈述一种事实，从句子后半句could have +过去分词我们可以推断前面没有收到我的电子邮件也是在发生在过去，且对现在产生了影响（还没有收到回信），因此这里用现在完成时，could have +过去分词。

89. It’s my mother who/that keeps encouraging me not to lose heart (一直鼓励我不要灰心) when I have difficulties in my study.
【解析】本题考察了强调句型和动词encourage的搭配。①强调句型it’s … that/who… ②encourage sb. (not) to do sth. 鼓励某人（不）做某事。

90. The publishing house has to consider the popularity of this novel. (考虑这本小说的受欢迎程度)。
【解析】本题考察了考虑的表达，可以用动词consider，也可以用词组take… into consideration。同时考生要注意名词popularity (受欢迎程度) 的拼写。

91. It’s wrong to define happiness only by money.(仅仅以金钱来定义幸福)