两个加数交换（ ）和不变，这叫做加法的交换律。

贾女士：本报对减肥成功者所作的一项调查显示，70%的受调查者称服用东参减肥丸，30%的称服用灵芝瘦身丹。没有被调查者服用其它减肥药。
陈先生：这说明在被调查者中，服用东参减肥丸的人数，比服用灵芝瘦身丹的两倍还多。
贾女士：另外，25%的被调查者称他们从不通过药物减肥。
以下哪项如果为真，最有利于解释贾女士的断定中看来存在的矛盾

A．30%的服用灵芝瘦身丹的被调查者，包括在70%的服用东参减肥丸的被调查者中
B．一些被调查者服用上述两种减肥药
C．被调查者的人数超过100人
D．被调查者在整个减肥成功者中，只占很小的比例

The amazing success of humans as a (91) is the result of the evolutionary development of our brains which has led, among other things, to tool-using, tool-making, the (92) to solve problems by logical reasoning, thoughtful cooperation, and language. One of the most striking ways in which chimpanzees biologically (93) humans (94) in structure of their brains. The chimpanzee, with the capacity for (95) reasoning, (96) a type of intelligence more like that of humans than (97) any other mammal living today. The brain of the modern chimpanzee is probably not too dissimilar (98) the brain that so many millions of years ago (99) the behavior of the first ape man.
For a long time, the fact that prehistoric people made (100) was considered to be one of the major (101) distinguishing them from other creatures. (102) pointed out earlier, I have watched chimpanzees (103) grass stems in order to use them to probe for termites. It is tree that the chimpanzee does not (104) tools to "a regular and set pattern"—but then, (105) people, before their development of stone tools, undoubtedly poked around (106) sticks, and straws, at which stage it seems (107) , that they made tools to a set pattern either.
It is because of the close (108) in most people’s minds of tools with humans (109) special attention has always been focused upon any animal able to use an object as a tool: but it is important to realize that this ability, on its own, does not necessarily indicate any special intelligence in the creature (110) .

A．prehistorical

B．easy

C．primitive

D．early

银行同业拆借以( )拆借为主。

A．6个月

B．4个月

C．隔月头寸

D．隔夜头寸

使用铁路冷藏车装运货物，如何计费？

酸性最强的是（）

A.大黄酸

B.大黄素

C.大黄酚

D.芦荟大黄素

E.大黄素-8-葡萄糖苷