调查某地1998年40~60岁正常男子血清总胆固醇含量。根据以往调查资料,估计

题型:单项选择题

问题:

调查某地1998年40~60岁正常男子血清总胆固醇含量。根据以往调查资料,估计血清总胆固醇均值为5.61mmol/L,标准差为0.95mmol/L, 容许误差不超过 0.176mmol/L,当α=0.05时。uα=1.96

根据题意,此资料提供的数据应该用于计算

A.参考值范围

B.总体均数可信区间

C.样本含量

D.t统计量

E.u统计量

考点:公卫执业助理医师公卫执业助理医师58
题型:单项选择题

以下哪项是主动脉瓣关闭不全所致().

A.SAM现象

B.弓背样改变

C.钻石样改变

D.吊床样改变

E.二尖瓣前叶高频震颤

题型:单项选择题

一小部分企业承担的平均存货都超过其基本需要。()

题型:单项选择题

Producing money requires both artistic and technological skills. Dollar bills are made so that they are interesting to look at but very hard to copy. In total, there are sixty-five separate steps required to make a dollar bill.

The money making process begins when. a yearly order is sent by the Federal Reserve Board. That order will then be divided in half. Half will be done here in Washington, D. C.and the other half will be done in Fort Worth, Texas. Next, the Bureau orders special paper which is actually cloth since it is 75% cotton and 25% linen.

This paper is made so that it can last a long time. And, it is made with details that make it hard to copy. For example, bills contain security threads. These narrow pieces of plastic are inside the paper and run along the width of the bill. This special paper is also made with very small blue and red fibers.

Once the money is printed, guillotine cutters separate the sheets into two notes, then into individual notes. The notes are organized in "bricks," each of which contains forty one-hundred-note packages. The bricks then go to one of twelve Federal Reserve Districts, which then give the money to local banks. Ninety-five percent of the bills printed each year are used to replace money that is in circulation, or that has already been removed from circulation.

You may know that America's first president, George Washington, is pictured on the one- dollar bill. But do you know whose face is on the two, five, ten, twenty, fifty and one hundred-dollar bills? They are, in order. President Thomas Jefferson, President Abraham Lincoln, Treasury Secretary Alexander Hamilton, President Andrew Jackson, President Ulysses Grant and statesman Benjamin Franklin.

The average life span of a one-dollar bill is twenty-one months. But a ten-dollar bill lasts only about eighteen months. The one hundred-dollar bill lasts the longest, eighty-nine months. One popular question is about the two-dollar bill. This bill is not printed very often. This is because many Americans believe two-dollar bills are lucky, so they keep them. 

小题1:During money production, we must consider all EXCEPT that it must                   .

A.last a long time

B.be hard to copy

C.be interesting to look at

D.be done by the president's order小题2:We can learn from the passage that the security threads                   .

A.are narrow pieces of plastic

B.are pressed outside the bills

C.are longer than the width of the bills

D.are actually made of cotton and linen小题3:How many presidents are printed on the American money?

A.Four

B.Five

C.Six

D.Seven小题4:Why are the two-dollar bills not made often?

A.Because no one wants them.

B.Because their material is a bit more expensive.

C.Because they aren't used in America any more.

D.Because they aren't damaged quickly like other bills.

题型:单项选择题

以下哪些说法是正确的( )

A.头孢克洛的药代动力学性质不稳定

B.头孢克肟对β-内酰胺酶不稳定

C.头孢呢酮3位乙硫代杂环取代,显示良好的药代动力学性质

D.头孢噻肟对β-内酰胺酶稳定

E.头孢噻吩钠的代谢发生在3位,生成没有活性的内酯化合物

题型:单项选择题

2013年12月3日,习 * * 在中 * * 政治局第11次集体学习时指出,在认识世界和改造世界的过程中不断把握规律、积极运用规律,才能不断开辟当代中国马克思主义发展新境界。这是因为,()。

A.人们在实践中可以认识或发现规律

B.规律是事物中本质的必然的稳定的联系

C.人们能够通过现代科学技术手段改变规律

D.人们可以改变规律发生作用的条件和形式

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