it is not polite.

　　For Americans，thumbs­up means yes，very good，or well done.Thumbs­down means the opposite.To call a waiter，raise one hand to head level or above.To show you want the check，make a movement with your hands as if you are singing a piece of paper.It is all right to point at things but not at people with the hand and index finger(食指)．Americans shake their index finger at children when they scold them and pat them on the head when they admire them.

　　Learning a culture's body language is sometimes confusing.If you don't know what to do，the safest thing to do is to smile.

5．From the first paragraph we can learn that________．

A．gestures don't mean anything while talking

B．gestures can help us to express ourselves

C．we can learn a language well without body language

D．only American people can use gestures

B　解析：推理判断题。从第一段首句"Sometimes people add to what they say even when they don't talk."可知，gesture language有自身的意义，能帮助我们表达，只能选择B项。

6．If you are introduced to a stranger from the U．S.A.，you should________．

A．greet him with a hug

B．place a hand on his shoulder

C．shake his hand firmly

D．shake his hand weakly

C　解析：推理判断题。从第二段中"people greet each other with a handshake in a formal introduction.The handshake must be firm."可获知，初次见面的时候，应该紧紧地握手。

7．In the United States，people often________．

A．show their friendship by touching each other

B．show their friendship by glancing at each other

C．say "Pardon me" to each other when they are talking

D．get uncomfortable when you sit close to them

D　解析：细节理解题。从三、四段可知，A、B、C三个选项是错误的。

8．When your friend gives you the thumbs­up，he，in fact，________．

A．shows his rudeness to you

B．shows his anger to you

C．expresses his satisfaction to you

D．expresses his worries about you

C　解析：推理判断题。从第五段首句"For Americans，thumbs­up means yes，very good