87. The professor required that ________________ （我们交研究报告）by Wednesday.

88. Though a skilled worker， _______________ （他被公司解雇了）last week because of the economic crisis.

89. It was reported that 65% of traffic accidents in this city _______________ （是由行车不慎造成的）.

90. ________________（希特勒是武装到牙齿的）when he launched the Second World War，but in a few years，he was completely defeated.

91.They are having a discussion ________________（目的是寻找改善质量的途径）.

87. hand in our research report
解析：句意为：教授要求我们在周三前交研究报告。由require引导的that宾语从句在表示指令性含义的时候应该用虚拟语气，即：require that sb. (should) do sth.通常should可以省略。

88. he was fired by the company
解析：句意为：虽然是个有经验的工人，但是由于经济危机他上周被公司解雇了。让步状语从句though和but绝对不能同时出现在一个句子里。 "解雇"可以翻译成fire，dismiss等

89. arose from careless driving
解析：行车不慎"可以翻译成careless driving；"由……造成"用arise from。arise主要用于指无形的、抽象的东西的出现或产生；arise from表示"由……引起"，"因……产生"。

90. Hitler was armed to the teeth
解析： "武装到牙齿"对应的英语习语是be armed to the teeth。

91. to find ways to improve the quality
解析：本题考查不定式作后置定语。discussion是后置定语修饰的中心词。"目的是……"可以用in order to，so as to，to等来表示。