J.Martin指出，系统开发所建立的企业模型应具有若干特性，以下哪个不在其要求之列

解方程：（x²﹣3x+2）（x²+3x﹣2）=x²（x+3）（x﹣3）

常把宋词分为（），（）两派。前者以（），（）为代表，后者以（），（），（）为代表。

Sometimes people add to what they say even when they don’t talk. Gestures are the “silent language” of every culture. We point a finger or move another part of the body to show what we want to say．It is important to know the body language of every country or we may be misunderstood.

In the United States，people greet each other with a handshake in a formal introduction．The handshake must be firm．If the handshake is weak，it is a sign of weakness or unfriendliness．Friends may place a hand on the other’s arm or shoulder．Some people，usually women，greet a friend with a hug（拥抱）．

Space is important to Americans．When two people talk to each other，they usually stand about two and a half feet away and at an angle，so they are not facing each other directly．Americans get uncomfortable when a person stands too close．They will move back to have their space．If Americans touch another person by accident，they say “Pardon me” or “Excuse me”．

Americans like to look at the other person in the eyes when they are talking．If you don’t do so，it means you are bored，hiding something，or are not interested．But when you stare at someone，it is not polite．

For Americans，thumbs-up means yes，very good，or well done．Thumbs-down 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 signing 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（使糊涂的）．If you don’t know what to do，the safest thing to do is to smile．

小题1: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小题2:If you are introduced to a stranger from the USA，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小题3: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 stand close to them小题4:If you talk with an American friend，it’s polite to ________．

A．look up and down at your friend

B．look at the other person in the eyes

C．hide your opinion

D．look at your watch now and then

定期排污是定期排除炉水中的（），其排污地点是（）。

处方中缩写为i．v．的中文含义（）

A.隔日一次

B.静脉注射

C.滴眼剂

D.眼膏剂

E.隔日一次静脉注射