87、Because of noise outside,Nancy had great difficulty________(集中注意力在实验上).
　　88、The manager never laughed;neither________(她也从来没有发过脾气).
　　89、We look forward to____________________( 被邀请出席开幕式).
　　90、It is suggested that the air conditioner ____________________(要安装在窗户旁边).
　　91、The 16 year old girl decided to travel abroad on her own despite______(她父母的强烈反对).

　　参考答案
　　87、focusing on the experiment
　　88、had temper before
　　89、being invited to attend the opening ceremony
　　90、is to be installed next to the window
　　91、her parents' strong opposition