A team of scientists the effects of acid rain over the last twenty-year period．( )A．studiedB．had studiedC．is studyingD．has been studying 题目和参考答案——青夏教育精英家教网—

题目内容

11．A team of scientists _____ the effects of acid rain over the last twenty-year period．（　　）

	A．	studied		B．	had studied
	C．	is studying		D．	has been studying

分析一组科学家在过去20年里一直在研究酸雨的影响．

解答答案：D．
根据时间状语over the last twenty-year period可知用现在完成进行时，表示从过去开始的动作持续到现在且一直还将进行下去，表达了他们的执着精神；故选D．

点评分清楚不同时态的具体用法，尤其是现在完成进行时表达强烈的语气这一用法．

练习册系列答案

2．Clearly and thoughtfully________，the book inspires confidence in students who wish to seek their own answers．（　　）

19．他在记者会上的言行相当出乎意料，以至令所有在场的记者均不知所措．（present）

6．你们俩若要合作，必须清楚地意识到你们不可能改变对方的个性而应学着相互尊重．（aware）Ifyoutwowanttocooperate，youmustbeclearlyawarethatyoucan'tchangethepersonalityoftheotherbutshouldlearntorespecteachother．．

16．Fresh milk _____ in the fridge，or it will go bad．（　　）

3．-Are you ready for the history test tomorrow？
-No，I wish I ______ the clock back．（　　）

	A．	had turned		B．	could turn
	C．	will turn		D．	would have turned

11．He was wearing a veryserious （严肃的）expression and I knew something was wrong．

2．I think watching TV every evening is a waste of time--there are meaningful things to do．（　　）

试题分类