把一块长方形木板截去一角，那么剩下的木板是（ ） A．五边形 B．四边形 C．三

阅读理解。

     Students often want to practice their English outside class. One of the best ways to practice your English

is to speak to a foreigner. This week's question comes from a student who is eager to start a conversation

with the foreigners he sees every day. One student asks, "Is it Okay to try to talk to foreigners I see in the

street?"

     The answer is yes or no, but probably no! If you see a foreigner who looks lost, it is polite to ask him,

"May I help you?" But, otherwise, you should probably let them get on with their business. Situations,

however, do exist (存在) where it is quite all right to talk to foreigners. If a foreigner enters your school,

office, shop or restaurant, for instance (例如), feel free to ask him (for example): 

     — What is your name? 

     — Where do you come from? 

     — What do you think of Beijing? 

     — How long will you stay in Beijing?

     There are also situations where it's Okay to talk to foreigners in public places. If you see a foreigner

alone in a restaurant, bar or coffee shop, it may be appropriate (合适的) to ask him or her:

     — Is this seat free? 

     — Do you mind if I talk to you in English?

     You can probably help them if they are new to China and if they are alone. You may be able to make them

feel more welcome. 

     After a few such questions, you should know whether this person wants to talk to you or not. If they ask

you similar questions, or if they give long, informative answers, you're in luck. If not, then give them their

privacy (独处). Talking to strangers is fun if you choose the right time and place.

1. It is the best way to practice your spoken English with _____. [ ]

A. Japanese

B. Americans

C. your classmates

D. French people

2. From the second paragraph, we can get to know that _____. [ ]

A. it is polite to stop a foreigner to talk with him in the street

B. it is polite to interrupt foreigners in a conversation

C. it is impolite to interrupt a foreigner when he or she is on business

D. it is impolite to help a foreigner find his way

3. When you first meet a foreigner, you should say "_____". [ ]

A. Where are you going?

B. Have you eaten your dinner?

C. Can you help me with my English?

D. Nice to meet you.

4. The writer suggests us that we should _____. [ ]

A. follow the foreigners when we meet them in the street

B. talk with foreigners in an accepted way

C. have a meal with foreigners in a restaurant

D. move to a place where a foreigner lives

5. This passage comes from a newspaper in column _____. [ ]

A. Sports

B. Health

C. Language

D. Business

带负电基团的有机物线型大分子，进入阴树脂后和带正电的固定基团发生电性复合作用不易再生，树脂颜色呈（），为重度污染。

A.淡草黄色

B.琥珀色

C.棕色

关于电荷所受电场力和洛伦兹力，正确的说法是（　　）

A．电荷在磁场中一定受洛伦兹力作用

B．电荷在电场中不一定受电场力作用

C．正电荷所受电场力方向一定与该处电场方向一致

D．电荷所受的洛伦兹力不一定与磁场方向垂直

如果表达式x=y*z中的“*”是作为成员函数重的运算符，采用运算符函数调用格式，该表达式还可以表示为______。

小额支付系统多采用批量处理、全额结算方式。（）