问题 单项选择题

如果在网络入口处封锁了TCP和UDP端口21、23和25,下面那种应用可以访问该网络______。

A.FTP
B.DNS
C.SMTP
D.Telnet

答案

参考答案:B

解析: 本题考查网络端口号与网络服务的对应,应试者应记住这些对应关系。
端口21对应服务FTP;端口23对应服务Telnet;端口25对应服务SMTP。而DNS的端口号为53。

阅读理解

阅读理解。    

     Last month I went to stay with my cousin Ken, who is a vet. I've always been interested in animals.

I wanted to have a week's work experience with a vet, so it seemed a good idea.  My cousin Ken is

friendly and easygoing, so I stayed with him, too. We had a lot of laughs.

     In their practice, they do a lot of "small-animal" work. In other words, they look after people's pets,

and don't work much with farm animals. Even so, it was very interesting. During the week I helped as

much as I could.  I cleaned out the animals' cages and boxes, as some of them are kept in the building

for a night or a couple of days.  I also fed them.  I looked after the owners when they arrived with their

pets, and made cups of tea and coffee for the two vets and the assistant. I watched all the operations

that were done and asked lots of questions.

     On my last day, I helped in an operation on a cat, which had a bad leg.  Sometimes a vet needs

another pair of hands. The cat lived, by the way!

     I wasn't sure what a vet's job would be like, and I found it was very interesting.  I learnt that a vet

needs a lot of scientific knowledge. Science isn't my best subject, therefore I feel that it is not a job for

me. Even so, I'm still pleased with the work experience that I had.  It's a great help while you're trying

to make up your mind.

1. Which of the following is TRUE?

A. There were good reasons for the writer to stay with Ken for a week.

B. The writer had expected to stay with Ken before.

C. The writer didn't feel happy until he stayed with Ken.

D. Ken wasn't friendly until the writer stayed with him.

2. From the second paragraph, we know _________.

A. vets like Ken don't do a lot of work with farm animals

B. the writer helped them less and asked more

C. there were more farm animals than small animals there

D. the writer could do the operations on the animals

3. Sometimes the vets were _________.

A. very worried about the cat        

B. very busy

C. sorry for the animal's death        

D. sure what they did

4.The underlined sentence "it is not a job for me" means _________.

A. the writer knew a vet's job well

B. the writer didn't want to do that kind of job

C. the job didn't interest the writer

D. he didn't like science at all

单项选择题