1.What does the underlined word "depleted"mean in paragraph 2?A.Stored upB.Used up.C.Absorbed.D.Enriched. 2.What is the third paragraph mainly abou...

Sayng1.What caused the decline of the whale population in the 20th century?A.Habitat loss.B.The climate change.C.Uncontrolled hunting.D.The ocean poll...

1.What's the purpose of NS Live?A.To set moral and commercial rules for the study.B.To encourage more women to devote to science.C.To demonstrate the...

1.What influence did the 11th grade teacher have on the author?A.Giving him a strict rule to follow.B.Changing his former reading habit.C.Instructing...

2.实验推动了人们对于光本质的研究，关于以下实验，下列说法正确的是红光通过宽度不竖直放置的肥皂同的单缝出现衍膜因干涉出现水射现象彩色条纹甲用乙用弧光灯照...

2.已知直线l1:(a+sin30)x+y+1=0,l2:x+√3tan120°y+2=0,若l1⊥l2,则实数a的值为7A.-522D.G 知直线x+3y+入=0与直线2x+6y+1=0间啊距离为)，则A=A.、9或B.-9C.-9或1...

3.已知四面体PABC中，点D,E分别为AB,PC的中点，若DE=xAP+yAC+zAB,则x,y,z分别为A.-1,11P2’2’-2E111’2A111C.-2’2’4D111BD.’2 4.在直三棱柱ABC-A1B,C1中，AA1=2...

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2.如图所示为磁流体发电机原理图，足够大行金属板A、B之间有一个很强的磁场，将一束等离子体（重力不计）喷入磁场，A、B两板间便产生电压从而向外供电，下列说法...

3.已知a>b且a+b=2,则下列结论错误的是A.a>1B.a2>abC.ab >b2D.a2+b2>24.已知函数f(x),g(x)满足f(x)=eg(x),若f(x)-f'(x)=e+,则g'(x)=A.exB.-el-*C.eD.-e 5.已知...

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