以下光缆的命名中，属于在本地网层面的唯一命名的有（）。
A.中继光缆
B.主干光缆
C.配线光缆
D.联络光缆
参考答案：A, B, C, D
用所给词的适当形式填空。
1. It's ten ________ ( mile) from my home to school.
2. Yesterday, I ________( ride) to school in five minutes.
3. Her father is ________(illness) in bed. She has to look after him at home.
4. In Hubei Province, there are many ________ ( town) lie beside the Yangzi River.
5. My mom ________(worry) about my sister because she didn't come back until 10 o'clock.
6. It took him 3 hours _________( buy) clothes.
疫苗是指为了预防、控制传染病的（）、（），用于人体预防接种预防性生物制品。
