中国营养学会制定的DRIS中，成人氟的UL值为（）A、1.0mg/d B、2.0mg/

阅读理解。

       Many children use the Internet to get useful knowledge and information, and to relax in their free time. But

some of them are not using in a good way. Here are some rules to make sure you are safe and have fun on the

Internet.

       ● Make rules for Internet use with your parents. For example, when you can go online, for how long and

what activities you can go online.

       ● Don't give your password (密码) to anyone else, and never leak out the following information — your

real name, home address, age, school, phone number or other personal information. 

       ● Check with your parents before giving out a credit (信用) card number.

       ● Never send a photo of yourself to someone in e-mail unless your parents say it's OK.

       ● Check with your parents before going into a chat room. Different chat rooms have different rules and

attract different kinds of people. You and your parents must make sure it's a right place for you.

       ● Never agree to meet someone you met on the Internet without your parent's permission (允许). Never

meet anyone you met on line alone.

       ● Always remember that people online may not be who they say they are. Treat everyone online as

strangers.

       ● If something you see or read online makes you uncomfortable, leave the site. Tell a parent or teacher

right away.

       ● Treat other people as you'd like to be treated. Never use bad language.

       ● Remember-not everything you read on the Internet is true.

1. If you want a true friend on the Internet, you can ______. [ ]

A. tell the people what your name is.

B. meet the people on line alone.

C. write an e-mail about yourself.

D. get your parent's permission.

2. It's good for children to _______ on the Internet. [ ]

A. give password to others

B. get useful knowledge and information

C. give out a credit card number

D. go into a chat room as they'd like to

3. The underlined phrase "leak out" in the third paragraph may mean " _______". [ ]

A. give away

B. leave out

C. give out

D. put away

4. If your parents don't agree, never _______. [ ]

A. read anything on the Internet

B. relax in your free time

C. have a face-to face meeting with anyone you met online

D. treat other people as you'd like to be treated

5. This passage is mainly about " ________". [ ]

A. How to use Computers

B. Surfing on the Internet

C. Information on the Internet

D. Internet Safety Rules

下列机动车辆保险的除外责任中，（）不是机动车商业第三者责任保险的除外责任。

A.被保险人或其允许的驾驶员所有或代管的财产

B.人工直接供油、高温烘烤造成的损失

C.本车上的一切人员和财产

D.私有、个人承包车辆的被保险人或其允许的驾驶员及其家庭成员，以及他们所有或代管的财产

下列记账凭证中，必须附原始凭证的有（）。

A.所有收款凭证

B.所有付款凭证

C.所有转账凭证

D.用于结账的记账凭证

如图所示的四个实例中，目的是减小摩擦的是[ ]

A、

B、

C、

D、

试回答下列问题：

（1）指出下面物质分子或离子的空间构型：PO₄^3－____________________；CS₂____________________。

（2）有两种活性反应中间体微粒，它们的微粒中均含有1个碳原子和3个氢原子。请依据下面给出的这两种微粒的球棍模型，写出相应的化学式：

A：________________；B：________________。

（3）按要求写出第2周期非金属元素构成的中性分子的化学式：平面形分子________________，三角锥形分子________________，四面体形分子________________。

（4）下列一组微粒中键角由大到小顺序排列为________（用编号填写）

①HCN；②SiF₄；③SCl₂；④CO₃^2－；⑤H₃O^＋