问题 多项选择题

下列哪两种说法正确描述了IEEESTP的功能()

A.它会立即将不处于丢弃状态的所有端口转换为转发状态

B.它提供了一种在交换网络中禁用冗余链路的机制

C.它有三种端口状态:丢弃、学习和转发

D.它可确保交换网络中没有环路

E.它可在不到1秒的时间内使交换网络收敛

答案

参考答案:B, D

填空题

阅读下面短文,根据上下文填入适当的词语,或使用括号中的词语的适当形式填空。

     Foreign students are valuable to the United States. Many take 1_____ in important research. Most have

to 2_____ the full costs for their education. That helps universities meet their budgets. International students

and their 3_____ put 12,000 million dollars into the American economy last year. That number is from the

Institute of International Education, based in New York.

     Now, many education officials say they are concerned that 4_____ students will come to the United States

for the next school year. The officials base their concern partly on a decrease in students 5_____ (plan) to

attend intensive English programs during the summer.

     The members said one reason 6_____ the expected decrease is slower and more restrictive United States

action on travel documents. 7_____ (secure) has increased since the terrorist attack of September 11,2001.

The schools also blamed the travel problems caused by the outbreak of SARS.

     In recent years, 8_____ increasing number of students have come to the United States to study. The

Institute of International Education says these students represent more than four percent of all students in

American colleges and universities. 9_____ says the number of international students reached a 10_____ high

of more than 580,000 last year. The largest number came from India. Before last year largest number came

from China.

单项选择题 B1型题