阅读短文，把A~E五个句子填入文中空缺处，使短文内容完整。

Today, privacy (隐私) has become an important part of our lives, especially for teenagers using the Internet. When teenagers post, share and communicate online, they leave behind some personal information. The information is not easy to delete completely. That’s why it’s important for teenagers to develop safe online habits. ____46____

◆ Use privacy settings (设置). ____47____ Teenagers should manage who can see their posts and private information, and only accept connections from people they know.

◆ ____48____ Teenagers often share their school names or vacation plans. It can be dangerous. Even one piece of information can be misused by strangers, or can lead to unwanted attention.

◆ Understand the risks of public Wi-Fi. Public Wi-Fi networks, like those in shops, are convenient but are not safe. When teenagers are online, they may not even realize that criminals can easily get their information. ____49____

◆ Show politeness online. Responsible Internet users care about not only themselves but also their influence on others. Teenagers should treat others politely. ____50____ Teenagers should think carefully before expressing their ideas, especially when they are angry. They shouldn’t talk about things they may regret.

By understanding privacy risks, managing personal information carefully, and developing safe online habits, teenagers can protect themselves better.

A. This is the first line to protect privacy.

B. Avoid sharing too much personal information.

C. Here is some advice on how to protect privacy online.

D. Being polite can stop them from becoming bad examples.

E. For this reason, they should use public Wi-Fi less if possible.

1.46.

A

B

C

D

解析：选C。承上启下总起句 空格前提出问题：青少年要养成安全上网、保护隐私的习惯；下文用◆列出四条具体建议。C 承接上文提出的话题，总领下文所有分点建议。排除其他：A 是对隐私设置的评价；B 是第二条小标题；E 对应公共 WiFi 段落；D 对应礼貌上网，都只能对应某一个段落，不能总领全文。

2.47.

A

B

C

D

解析：选A。细节逻辑句（指代衔接）。本段主题：Use privacy settings（使用隐私设置）。This 指代上一句的 “使用隐私设置” 这件事。句意：使用隐私设置，是保护隐私的第一道防线，后面继续解释该如何操作隐私设置。解题线索：代词This就近指代前文提到的做法。

3.48.

A

B

C

D

解析：选B。段落小标题（主旨句）。本空是◆引导的小标题，概括整段中心。后文：青少年常分享校名、假期计划；信息会被陌生人滥用，带来危险。整段围绕 “不要过度泄露个人信息” 展开。B 完美概括段落主旨。

4.49.

A

B

C

D

解析：选E。因果逻辑句。前句说明原因：公共 WiFi 不安全，不法分子容易盗取信息。For this reason（正因如此）承接前面的危险情况，引出建议结果：尽量少用公共 WiFi。解题线索：For this reason是因果逻辑标志词。

5.50.

A

B

C

D

解析：选D。细节逻辑句。本段主题是Show politeness online网上讲礼貌。前句：青少年应当礼貌对待他人；后句：表达想法前要三思，不说后悔的话。D 句解释为什么要网上讲礼貌：礼貌能够避免自己成为坏榜样，上下文话题统一，复现关键词 polite /politeness。