根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
If you're a kid who likes to have fun and chat with friends online, here's how you can stay safe and avoid problems.
Stick to safer sites. Your parents and teachers can guide you to the best sites for you. Some sites have age restrictions（限制）, so you might want to lie about your age. ____16____
Guard your passwords. If someone can sign in（登录）as you you will have no control over what they do or say. ____17____ So don't share your passwords with anyone except your parents.
Limit what you share. ____18____ If you're not sure if you should share something, ask a parent. Remember that anything you put online or post on a site is there forever, even if you try to delete it. If you wouldn't want your class to know or see something, you shouldn't share it with anyone online, not even your best friends.
____19____ Tell an adult right away if someone says something to you that makes you uncomfortable. Also tell an adult if you see anyone bullying（欺凌）or saying strange things to other kids.
Be choosy about your online friends. Some sites let kids make friends with people they don't know. ____20____Never agree to meet an online friend in person or give out personal information about yourself.
A. Always tell if you see strange or bad online behavior.
B. But online friends are not the same as the friends in real life.
C. It's safer to tell the truth and avoid those sites until you're older.
D. We should be hard on other people online.
E. And everyone will think it's you!
F. Communicate more with your friends.
G. Never tell a stranger where you live or your phone number.
【答案】16. C    17. E    18. G    19. A    20. B
本文是一篇说明文，文章从五个方面告诉了我们安全上网的策略。
16.C【解析】句意：在你长大之前，说出真相并避免这些网站更安全。
根据上文“Stick to safer sites…Some sites have age restrictions（限制）, so you might want to lie about your age”可知，有些网站有年龄限制，所以你可能谎报自己的年龄点击这些不安全的网站，故“在长大之前，说出真相并避免这些网站更安全”承接上文，符合语境。故选C。
17.E【解析】句意：每个人都会认为这是你！
根据上文“If someone can sign in（登录）as you, you will have no control over what they do or say”可知，如果有人以你的身份登录，你将无法控制他们的言行，因为每个人都会认为这是你自己本身，故“每个人都会认为这是你”符合语境。故选E。
18.G【解析】句意：永远不要告诉陌生人你住在哪里或你的电话号码。
根据下文“you shouldn't share it with anyone online, not even your best friends”可知，本段主要介绍不要随意在网上发布自己的私人信息，一旦信息被分享到网络就很难再删除，故“永远不要告诉陌生人你住在哪里或你的电话号码”符合本段语境。故选G。
19.A【解析】句意：总是告知成人你是否看到奇怪或不良的网上行为。
根据下文“TAlso tell an adult if you see anyone bullying（欺凌）or saying strange things to other kids”可知，当你看到一些奇怪的或者不良的网络行为时，要及时的告知成年人，故“总是告知成人你是否看到奇怪或不良的网上行为”符合本段语境。故选A。
20.B【解析】句意：但是网上朋友和现实生活中的朋友是不一样的。
根据“Be choosy about your online friends”及本段内容可知，本段与网上交友有关，我们不能独自一人去约见网友或者给出自己的个人信息，故“但是网上朋友和现实生活中的朋友是不一样的”符合本段语境。故选B。