月经将至时的月经常脉的表现是（） A.弦 B.滑 C.数 D.浮 E

(10分)某课外兴趣小组欲测定某NaOH溶液的浓度，其操作步骤如下：

①将碱式滴定管用蒸馏水洗净后，用待测溶液润洗后，再注入待测溶液，调节滴定管的尖嘴部分充满溶液，并使液面处于"0"刻度以下的位置，记下读数；将锥形瓶用蒸馏水洗净后，用待测溶液润洗锥形瓶2～3次；从碱式滴定管中放入20.00mL待测溶液到锥形瓶中。

②将酸式滴定管用蒸馏水洗净后，立即向其中注入0.1000mol/L标准硫酸，调节滴定管的尖嘴部分充满溶液，并使液面处于"0"刻度以下的位置，记下读数。

③向锥形瓶中滴入甲基橙作指示剂，进行滴定。滴定至指示剂刚好变色，且半分钟内颜色不再改变为止，测得所耗硫酸的体积为V₁mL。

④重复以上过程，但在滴定过程中向锥形瓶加入5mL蒸馏水，测得所耗硫酸为V₂mL。

试回答下列问题：

（1）锥形瓶中的溶液从         色变为　   　色时，停止滴定。

（2）滴定时边滴边摇动锥形瓶，眼睛应注意观察                

（3）上述操作步骤中两处错误分别是                               ，

                                           (请指出具体错误)。由此造成的测定结果分别是        ，  　　 (填偏高、偏低或无影响)。

（４）某次滴定时的滴定管中的液面如图，则其读数为      mL。若记录读数时，起始时俯视，终点时仰视，则所测溶液浓度会           (填偏高、偏低或无影响)。

（５）根据下列数据：

滴定次数	待测液体积(mL)	标准硫酸体积（mL）
		滴定前读数（mL）	滴定后读数（mL）
第一次	20.00	0.50	25.45
第二次	20.00	4.00	29.05

请计算待测烧碱溶液的浓度为             mol/L。

阅读理解。

     We often hear people talking about a generation gap (代沟). The name is new, but the idea

is old. Young people and their parents don't understand each other. The world has always kept

changing. During the second century after Christ a wise man said, "Bury me on my face because

in a little while everything will be turned upside down."

    There has always been a gap between generations, but more people talk about it now. Old

Mr. Ellis thinks he understands what has happened.

    "When I was a boy, I thought the world was a beautiful place. My life was very pleasant. But

when I was older, I learned about people who were treated badly, people who didn't have enough

to eat. I wanted to help them, and I married a girl who wanted to help them, too. We went to

meetings and talked a lot, but it didn't seem to make much difference. "

    "Our children grew up in a world at war. They didn't know when the fighting would stop. They

wanted their children to have nice clothes and toys. They didn't want to think about the future.

They thought nothing could be done about it."

    "Now I have grandchildren, and they have their own ideas. They are trying to make the world

better. They are trying to help other people. They're making people listen to them. I am proud

of their generation."

1. The wise man mentioned in the text told people to bury him on his face so that when everything

is turned upside down he will _____.

A. lie on his stomach        

B. lie on his back

C. stand quietly        

D. sit in peace

2. Which generation did NOT want to do anything to make the world a better one?

A. Mr. Ellis' generation      

B. His children's generation

C. His grandchildren's generation  

D. None of the above.

3. Which generation is/was more efficient in making the world better one?

A. Mr. Ellis' generation.          

B. His children's generation.

C. His grandchildren's generation.

D. None of the above.

4. What is the writer's attitude towards the generation gap?

A. Unacceptable.    

B. Awful.    

C. Funny.      

D. Common.

在物理学建立的过程中，有许多伟大的科学家做出了贡献。关于科学家和他们的贡献，下列说法正确的是

A．英国物理学家焦耳在热学、电磁学等方面做出了杰出贡献，成功地发现了焦耳定律

B．英国物理学家、化学家卡文迪许利用卡文迪许扭秤首先较准确的测定了静电力常量

C．德国天文学家开普勒对他导师第谷观测的行星数据进行多年研究，得出了万有引力定律

D．古希腊学者亚里士多德认为物体下落快慢由它们的重量决定，牛顿在他的《两种新科学的对话》中利用逻辑推断使亚里士多德的理论陷入了困境

1999年8月以（）通过国内第一步青年志愿者服务条例开始，青年志愿者服务的立法工作开始一步步取得成绩。

A.广东人大

B.天津人大

C.上海人大

D.北京人大

已知全集U=1，2，3，4，5，6，7，8，M=1，3，5，7，N=5，6，7，则

=（）.

A．5，7

B．2，4

C．2，4，8

D．1，3，5，6，7