PREP遇到一道数学和两道语法不会，请教~~~

dolorez

The postive integer k has exactly two positive prime factors,3 and 7.If k has a total of
6 positive factors,including 1 and k,what is the value of k?
1. 9 is a factor of k
2. 49 is not a factor of k

三.There is a widespread belief in the US and Western europe that young people have a smaller
commitment  to work and a career than their parents and grandparents and that the souce of
the change lies in the collape of the work ethic.
A. a smaller commitment to work and a career than their parents and grandparents
B. less of a commitment to work and a career than their parents and grandparents
C. a smaller commitment to work and a career than that of their parents and grandparents
D. less of a commitment to work and a career than their parents and grandparents had
E. a lessening of the commitment to  work and a career than their parents and grandparents had

四. Discussion of greenhouse effects has usually focused on whether the Earth would harm and
by how much,but climatologists have indicated all along that the most obivious effects, and
those that would have the largest impact on people,would be extremes of temperature,precipitation and storminess.
A. the most obivious effects, and those that would have the largest impact on people,would be extremes of temperature,precipitation and storminess.
B. the effects that are the most obivious effects, extremes of temperature,precipitation and storminess,would be those impacting the most on people.
C. those effects to have the largest impact on people,extremes of temperature,precipitation and storminess,are what are the most obivious effects.
D. extremes of temperature,precipitation and storminess,the most obivious effects,that they would have the largest impact on people.
E. extremes of temperature,precipitation and storminess,which are the most obivious effects,are those to impact the most on people.

ggghost

一般情况下;
2个不同质因素时，因数个数 [1，A, B, AB]=4个
3个不同质因数时，因数个数 [1，A，B，C，AB，AC，BC，ABCD]=7个
此题说 k has exactly two positive prime factors,3 and 7，并且有6个因数。所以不可能是3个不同的质因素，否则应该会有7个因素，其次不可能仅有两个质因数，因为那样K就是21，那一共只有3个因素
所以K应该除了3，7，外，包含另一个重复的因素3或7，通过题干K=63or 147,接下来就容易判断了

wy215

我觉得第一题的答案应该是D.
在学校自助机房，身边没有草稿纸，只有卫生纸。感叹一下：现在的卫生纸质量怎么那么差，我记得初中的时候草纸完全可以当草稿纸用的，现在的怎么一写就破~~

-- by 会员 wy215 (2009/12/25 20:49:38)

。。。。。。

小孩儿 你要期末考试~

-- by 会员 yigaohanxi (2009/12/25 21:56:35)

yigaohanxi

我觉得第一题的答案应该是D.
在学校自助机房，身边没有草稿纸，只有卫生纸。感叹一下：现在的卫生纸质量怎么那么差，我记得初中的时候草纸完全可以当草稿纸用的，现在的怎么一写就破~~

-- by 会员 wy215 (2009/12/25 20:49:38)

。。。。。。

小孩儿 你要期末考试~

wy215

1)9是它的因子，证明3出现了两次，也就是说k = 3 *3*7.此时，它已经符合条件了。
2）49不是，证明7不能出现两次。那么考虑让3出现两次，这时候发现也符合了。所以都有效

dolorez

一楼啊

wy215

是的，，请赐教哦

-- by 会员 dolorez (2009/12/25 21:18:19)

LZ，哪个right？你倒是公布一下正确答案啊~~这边两个答案耶~~~

dolorez

是的，，请赐教哦

wy215

我觉得第一题的答案应该是D.
在学校自助机房，身边没有草稿纸，只有卫生纸。感叹一下：现在的卫生纸质量怎么那么差，我记得初中的时候草纸完全可以当草稿纸用的，现在的怎么一写就破~~

zscsl

楼主的那位美女。。。
答案是什么哟。。。