根据下句子的意思及所给的汉语提示，写出空缺处单词、固定短语或固定搭配的正确形式。

1. After dinner, taking a walk can keep you _______ (健康).

2. The plane _______ (起飞) in half an hour. Let's get ready.

3. _______ (树叶) turn green when spring is coming.

4. My clock _______ (响) every day.

5. We have to stay at home. It's raining              (大).

为了防止Web服务器与浏览器之间的通信内容被窃听，可以采用的技术为( )。

A．身份认证

B．NTFS分区

C．SSL

D．FAT32分区