慢性肾衰竭出现（） A.腹泻、呕吐 B.严重贫血、多尿、夜尿等，并伴有部分尿毒症中毒

根据短文内容，选择正确答案。

     My friend Bob has an interesting hobby. He likes collecting stamps. He spends a lot of time on his

stamp collection after school hours. Now he has hundreds of stamps from all over the world.

     Bob likes stamps with pictures of animals and plants on them. In this way, he learns the names of

many animals and plants. He also borrows books on animals and plants from his school library. He learns

a lot from them.

     Sometimes Bob has many stamps of the same kind. He gives some of them to his friends. And they

give him others in return (回报).

     Bob often writes to his friends in many countries. He sends them stamps of his country. In return, they

send him stamps of their countries. 

     Bob thinks collecting stamps can bring him much knowledge, pleasure and happiness. And he can

make more friends from all over the world.

1. Bob spend a lot of time on his hobby ______.

A. during his holiday

B. after school hours

C. during school hours

D. on Sundays

2. Bob learns a lot about animals and plants from ______.

A. his teachers

B. his friends

C. his stamps      

D. his classmates

3. When Bob has stamps of the same kind, he ______.

A. sells them to his friends

B. throws then away

C. keeps them for himself

D. sends some of them to his friends

4. Bob often sends some stamps to his friends in many countries, and the friends ______.

A. send him other stamps in return

B. write him letters for thanks

C. give him some money

D. send him some foreign coins

5. Collecting stamps can make Bob ______.

A. very happy

B. learn much knowledge

C. make more friends

D. A, B and C

欧洲的居民以    (    )

A．黑种人为主

B．黄种人为主

C．混血种人为主

D．白种人为主

下面关于漏洞扫描系统的叙述，错误的是（ ）。

A．漏洞扫描系统是一种自动检测目标主机安全弱点的程序

B．黑客利用漏洞扫描系统可以发现目标主机的安全漏洞

C．漏洞扫描系统可以用于发现网络入侵者

D．漏洞扫描系统的实现依赖于系统漏洞库的完善

计算机硬件系统中最核心的部件是（）

A.主存储器

B.磁盘

C.CPU

D.输入/输出设备

按原因分最常见的肺炎是

A．病毒性肺炎
B．肺炎球菌肺炎
C．肺炎杆菌肺炎
D．大叶性肺炎
E．支气管肺炎