within under towards upon_大学三级

    within、under、towards、upon 

    问:the survival of civilization as we know it is ____ threat . 

    鶤) within b)under c)towards d)upon 

    解:句意为:"当今人类文明的生存正在受到威胁。"在4个选项中,只有b) under 

    表示"在…..情况下"或"遭到"。 

    鶬s under threat 相当于 is experiencing threat .故b)under 为解。如: 

    鶧id he do it voluntarily or under compulsion ? 他是自愿做的,还是强迫做的? 

    鶷he road was under repair so we had to go round .这条道路正在修理,因此我们只得绕道而行。 

    鶷he fire was soon brought under control .火势很快得到控制。 

    选项d)不能与threat 搭配表"遭遇"之意。upon 可以表示"在….后立即"。如: 

    鶸pon conclusion of these studies,the patient was told that she had a severe problem. 

    在这些研究一有结论之后,病人就被告知有严重的博towards 意为"向….对….."如: 

    鶷he talks made little evident progress towards agreement .谈判几乎没有向达成协议的方向取得进展。 

    问: by the end of this month , we surely ____ a satisfactory solution to the problem . 

    鶤) have found b)will be finding c) will have found d)are finding 

    解:本题考核谓语动词时态的用法。句中时间状语 by the end of this month (到本月底)表示未来的某一时刻,后面说"肯定能找到一个满意的解决问题的办法",即句子谓语动词的动作 find 要在该时刻前完成。因此需用将来完成时态。故答案为 c) 

    鷚ill have found .如: 

    鷚hen we get there they’ll probably have left 我们到那里时他们可能已经走了。 

    鶫e will have finished his novel by next friday .他将在下星期五前写好他的小说。