91. 他们要求我在下周五之前把借的书还回图书馆。
that I(should) return the books borrowed to
library /the books I borrowed (should) be returned to the library.
解析：
request 有“要求”的意思时，引导的宾语从句要用
request that
sb. (should) do sth.
虚拟语气，结构为：
2010年6月大学英语四级真题
Because of the
noise outside, Nancy had great
difficulty________（集中注意力在实验上）
87.
The manager never laughed;
88.
neither_______.（她也从来没发过脾气） .We look forward to ________.（被邀请出席开幕式）
89
It is suggested that the air
conditioner（要安装在窗户旁）
90.
The 16-year-old girl decided to
travel abroad on her own despite______ （他父母的强烈反对）
91.
