1.选择题- (共6题)
3.如果在一个种群中,基因型AA的比例占25%,基因型Aa的比例为50%,基因型aa的比例占25%。已知基因型aa的个体失去求偶和繁殖的能力,则随机交配一代后,基因型aa的个体所占的比例为
6.质量为M的小车放在光滑水平面上,小车上用细线悬挂另一质量为m的小球,且M>m.用一力F水平向右拉小球,使小球和小车一起以加速度a向右运动,细线与竖直方向成α角,细线的拉力为F1,如图(a).若用一力F′水平向左拉小车,使小球和车一起以加速度a′向左运动时,细线与竖直方向也成α角,细线的拉力为F1′,如图(b),则

2.单项选择- (共7题)
7.
What on ____ earth are you doing under such ___ burning sun? Go indoors.
A.the; the | B.an; a | C./; / | D./; a |
8.
Mr. Smith stood up in defence of the 16-year-old boy, saying that he was not the person ____.
A.blamed | B.blaming | C.to be blamed | D.to blame |
9.
The woman ____ herself a writer has never written any books.
A.calling | B.called | C.calls | D.to call |
10.
She is not very ____ about the idea of going camping. I think she will stay at home reading.
A.optimistic | B.enthusiastic | C.confused | D.curious |
11.
____ I understood very little French, I couldn’t follow their conversation.
A.Although | B.Unless | C.Since | D.Before |
试卷分析
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【1】题量占比
选择题:(6道)
单项选择:(7道)
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【2】:难度分析
1星难题:0
2星难题:0
3星难题:0
4星难题:0
5星难题:0
6星难题:7
7星难题:0
8星难题:0
9星难题:0