7.17一些机经

galoon

虽然考得很烂，但也奉献一些吧：

数学：
DS
1, m的n次方是perfect square?
a, m是perfect square
b, n是perfect square

2, a, b两个长方形面积相等，然后给出a,b长宽的关系，问a的dimension?
应该是15/9；

语法：
1，prep-43，就是cfc那题，选A；

RC看到前面的同志们写的差不多了；

CR只记得有一个关于湿地的题。还有记得再写吧。

望大家都有个好成绩。

Yune

LZ谢啦~~~

Justin12122

1 A

小小的蛋清

1，prep-43，就是cfc那题，选A；

lz可不可以说具体一点是那题啊？

辛苦~

Princika

perfect square什么意思啊？？？？？？

Justin12122

是这道题吧，，选A。

43.        (26724-!-item-!-188;#058&003285)

 

Although ice particles in the upper atmosphere benefit Earth in that they reflect and absorb solar radiation, acting as a global thermostat and thus keeping Earth from either burning up or freezing over, they also accelerate the destruction of the ozone layer by reacting with chlorofluorocarbons (CFC's).

 

(A) acting as a global thermostat and thus keeping Earth from either burning up or freezing over, they also accelerate

(B) acting as a global thermostat and thus keeping Earth either from burning up or freezing over, while also accelerating

(C) act as a global thermostat and thus keep Earth from either burning up or freezing over, while also accelerating

(D) they act as a global thermostat that thus keeps Earth either from burning up or freezing over, even though it also accelerates

(E) they act as a global thermostat to thus keep Earth from either burning up or freezing over, but they also accelerate

小小的蛋清

感谢感谢~

mjbluesio

1, m的n次方是perfect square?
a, m是perfect square
b, n是perfect square

这题怎么做呀？

Justin12122

以下是引用mjbluesio在2009/7/17 21:42:00的发言：

1, m的n次方是perfect square?
a, m是perfect square
b, n是perfect square

这题怎么做呀？

先看a, 设m=p^2.则m^n=(p^2)^n=p^2n也就是=p^n×p^n 是个完全平方数

再看b. 同样的代换办法发现当n为大于一的正奇数的时候不成立

msuzengli

2, a, b两个长方形面积相等，然后给出a,b长宽的关系，问a的dimension?
应该是15/9

这题怎么做? 怎么觉得条件没给全?