一、 There are 20 incomplete sentences in this section.For eac

一、 There are 20 incomplete sentences in this section.For each of these,there are 4 choices marked A,B,C,and D.Choose the ONE that best completes the sentence.
1.Children get parents ______ Christmas and ______ their birthdays.
A.on,at B.in,at C.at,on D.by,on
2.They talked ______ low voices in order not to be heard.
A.at B.by C.on D.in
3.She was ______ her twenties when she went abroad.
A.at B.in C.for D.of
4.There are many birds singing ______ the trees.
A.in B.on C.at D.with
5.Mike received an award ______ his outstanding results in the exams.
A.to B.about C.for D.with
6.Tom lost his way,______ delayed him considerably.
A.that B.when C.where D.which
7.If he ______ here I could explain to him myself.
A.is B.has been C.were D.was
8.The district grew peas ______ a large scale.
A.on B.in C.by D.to
9.I’m going to Paris ______ my brother is coming as well.
A.both B.or C.either D.and
10.The time has come ______ we can make extensive use of nuclear energy.
A.as B.when C.while D.since
11.The boss may ______ Tony because he has the right qualifications.
A.fire B.fine C.dismiss D.hire
12.He knew nothing about this journey ______ he was likely to be away for three months.
A.that B.except that C.however D.in addition
13.What time ______ for work?
A.are you usually leaving B.do you usually leave
C.you usually leave D.you usually left
14.______ you nervous during the interview?
A.Were B.Did C.Do D.Had