已知函数f(x)=lnx+1-xax,其中a为大于零的常数,若函数f(x)在区间

题型:选择题

问题:

已知函数f(x)=lnx+
1-x
ax
,其中a为大于零的常数,若函数f(x)在区间[1,+∞)内调递增,则a的取值范围是(  )
A.(-∞,1]B.(-∞,-1]C.[1,+∞)D.[-1,+∞)
考点:函数的单调性与导数的关系
题型:选择题

销售人员考核资料的主要来源包括()。

A.销售人员销售报告

B.产品供应商意见

C.企业销售记录

D.企业内部其他职员意见

题型:选择题

地下水中分布最广、含量较高的阴离子有()、()及()等。

题型:选择题

批转和转发性通知应怎样写?

题型:选择题

Passage Two

If there is one thing I’m sure about, it is that in a hundred years from now we will still be reading newspapers. It is not that newspapers are a necessity. Even now some people get most of their news from television or radio. Many buy a paper only on Saturday or Sunday. But for most people reading a newspaper has become a habit passed down from generation to generation.

The nature of what is news may change. What basically makes news is what affects our lives—the big political stories, the coverage of the wars, earthquakes and other disasters, will continue much the same. I think there will be more coverage of scientific research, though. It’s already happening in areas that may directly affect our lives, like genetic engineering. In the future, I think there will be more coverage of scientific explanations of why we feel as we do—as we develop a better understanding of how the brain operates and what our feelings really are.

It’s quite possible that in the next century newspapers will be transmitted electronically from Fleet Street and printed out in our own home. In fact, I’m pretty sure that how it will happen in the future. You will probably be able to choose from a menu, making up your own newspaper by picking out the things you want to read--sports and international news, etc.

I think people have got it wrong when they talk about competition between the different media. They actually feed off each other. Some people once foresaw that television would kill off newspapers, but that hasn’t happened. What is read on the printed page lasts longer than pictures on a screen or sound lost in the air. And as for the Internet, it’s never really pleasant to read something just on a screen.

From the passage,we can infer()·

A.newspapers will win the competition among the different media

B.newspapers will stay with US together with other media

C.television will take the place of newspaper

D.the writer believes some media will die out

题型:选择题

下列哪一种细胞内一般没有内质网()。

A、淋巴细胞

B、肝细胞

C、癌细胞

D、肾细胞

E、红细胞

更多题库