问题 选择题

某物质在氧气中燃烧,只生成二氧化碳和水,则下列说法中正确的是(  )

A.该物质中含有单质碳和氢气

B.该物质由碳、氢、氧三种元素组成

C.该物质中一定含有碳、氢两种元素,不含有氧元素

D.该物质中一定含有碳、氢两种元素,可能含有氧元素

答案

根据质量守恒定律,化学反应前后元素的种类不变,某物质在氧气中燃烧,反应物有两种,其中氧气只含有氧元素,产物只有水和二氧化碳,共含有碳、氢、氧三种元素,氧元素可能来自氧气,也可能来自某物质,不能确定;但氧气中无碳、氢元素,即某物质中一定含有碳、氢两种元素,故准确结论是:该物质中一定含C、H,可能含有O,所以D正确,

故选D.

阅读理解

(Q =" Question;" A = Answer)

Situation I

Q: If someone sits right next to me in an empty movie theater, is it rude to move?

A: Maybe, but nobody will fault you for it. Chances are that close sitter doesn't realize he disturbs you, so he may miss your annoyance. You undoubtedly aren't the first person he's met who needs enough room. Forgive his bad judgment, move quietly and enjoy the show.

Situation II

Q: If I use the bathroom at a store, do I need to buy something?

A: Consider frequency and urgency. Is this a one-time or an emergency? If so, you don't have to buy anything, but it would be kind if you did. However, if you regularly use the bathroom at this place, then you are a customer, and you should act like one.

Situation III

Q: If someone is talking loudly on the bus, is there a nice way to ask him to keep it down?

A: No. Try other means.1) Stare at him until he gets aware of it and quiets down. 2) Lift your finger in a silence motion(动作)and smile. 3) Put on earphones and ignore him.

Situation IV

Q: If I remember my friend's birthday a day late, should I apologize or just wish her a happy birthday like nothing happened?

A: This is the reason why the word belated was invented. "Happy belated birthday!" is short for: "Well, I know I forgot, but then I remembered. Forgive me and happy birthday."

Situation V

Q: Can I lie about seeing a text because I was too busy or lazy to respond(回复) to it?

A: Don't lie. Receiving a text does not mean you need to respond to it. Why waste a perfectly good lie when the truth will serve? "Yes," you can say if ever asked, "I saw it." No explanation is needed as to why you don't respond.

小题1:You will get annoyed in a theater when         .

A.a person is too active

B.a person is too rude to you

C.a person talks too loudly

D.a person sits too close to you小题2:How will you quiet someone down in a public place?

A.By making fun of him continuously.

B.By looking purposefully at him.

C.By talking to him directly.

D.By pointing angrily at him.小题3:The underlined word "belated" in Situation IV probably means      .

A.predicted

B.returned

C.cancelled

D.delayed小题4:What is the passage mainly about?

A.Modern ways to mind your manners.

B.Different ways to change others' manners.

C.Proper manners to offer help to others.

D.Good manners to talk to people.

判断题