10Base--5工作站到收发器的距离范围是 (42) 。最多使用 (43) 各中继器连接干线段。 10 Base-2 一个干线上最多支持 (44) 个工作站，它使用 (45) 来连接网络接口卡和电缆相连。细缆以太网10Base-2 连接点不需要使用 (46) 部件。10Base-T工作站连接至一个中心集线器或集中器，其作用相当一个 (47) ，它的拓扑结构是 (48) ，MAC层使用 (49) 协议。在以太网中，5类非屏蔽双绞线可以适用于物理层的 (50) 。
（47）处填（）。
A．路由器
B．网桥
C．中继器
D．工作站
参考答案：C
| 阅读理解。 | ||
你想知道中西方的节日有何不同吗？快来看看这两封电子邮件吧！
Today is the Mid-Autumn Festival. We will watch the moon tonight, and look for Chang'e and Wu Gang. We usually eat mooncakes. They are round, like the moon. National Day is also in autumn, on October 1st. My mother and father are usually free for seven days! We will do many things together. I like going to the National Day celebration. But the best thing in autumn is my birthday. It's in October. I will be fifteen years old. Goodbye. Yours, Li Ming
Thank you for your e-mail! I love autumn too. In Canada (加拿大), we have an autumn holiday called Thanksgiving Day. Family members always celebrate it together. I will go to my grandmother and grandfather's house. My uncles, aunts and their children will be there too. Canadian Thanksgiving Day is in early October. In the USA, they celebrate Thanksgiving Day in late November. Have a good time on your birthday, Li Ming! On my birthday, I have a cake with candles. Everyone sings the song "Happy birthday". Then I blow out the candles! Will you have a cake for your birthday? Your friend, Jenny | ||
| 1. — When is Li Ming's birthday? — ______. | ||
[ ] | ||
| A. On September 29th B. In September C. Before September 29th D. After September 29th | ||
| 2. Americans celebrate Thanksgiving Day ______. | ||
[ ] | ||
| A. in early October B. in early November C. in late October D. in late November | ||
| 3. — What do Canadians usually do on Thanksgiving Day? — They usually ______. | ||
[ ] | ||
| A. eat cakes B. stay together C. watch the moon D. sing a song | ||
| 4. The subject (主题) of Jenny's e-mail is "______". | ||
[ ] | ||
| A. Your birthday B. My birthday C. Thanksgiving Day D. National Day | ||
| 5. — What must Li Ming and Jenny use when they write to each other? — ______. | ||
[ ] | ||
| A. Pens B. Paper C. Computers D. Telephones |