87.doctors can treat this disease successfully.

　　88. In my sixties, one change I notice is that __ .

　　89. I am going to pursue this course, ___ .

　　90. I would prefer shopping online to shopping in a department store because ______

　　.

　　91. Many Americans live on credit, and their quality of life ___ __

　　, not how much they can earn.

　　详解：

　　87. Thanks to/ Because of/ Owing to/ As a result of a series of new inventions本题考查多亏了和一系列两个表达方法。

　　88. I am more likely to get tired than before. / it is more likely for me to become tired than before. / I am more inclined to become tired than before.本题考点是更容易，使用be more likely to或be more inclined to.

　　89. no matter what I have to sacrifice / whatever sacrifice I have to make本题考点无论和牺牲，如果不会拼写sacrifice,可用pay代替。

　　90. it is more convenient and less time-consuming / it is more convenient and time-saving. / it is more convenient and can save more time本题难点是省时，可用形容词或动词词组表示相同意义。

　　91. is measured/evaluated by how much they can borrow/loan本题难点是被动语态。