上消化道出血患者的粪便性状是（）。 A.灰白色便 B.黏液脓血便 C.米泔样便 D.

阅读与表达。

     Happiness is U-shaped, for we are happier at the start and end of our lives but hit a slump (低潮) when

we are middle-aged, scientists from England and America say. They have studied the information on the

mental (心理的) health of two million people from 80 countries.

     In England, the probability of low spirits for men and women reaches the highest point at around 44 years

of age. In America, though, there is a big difference between men and women. Among women, unhappiness

reaches the highest point at around the age of 40, but among men, it is about 50.

     But the U-shape of happiness is unchanging around the world, and the mid-life sadness happens regardless

of marital status (婚姻状况), changes in jobs or pay. It happens to men and women, to single and married

people, to rich and poor, and to those with and without children.

     One possibility may be that people realize many of their dreams won't come true at middle age. The

researchers said another reason could be that seeing their middle- aged friends die one by one, people begin to

value their own remaining years and their Iove of the nature and long for peaceful and free life once more.

     But the good news is that if people make it to aged 70 and are still physically fit, they are on average (平均)

as happy as a 20-year-old person. For the average people in the modem world, the fall in mental health and

happiness doesn't come on suddenly in a single year. Only in their fifties do people get out of this low period.

1. Do people feel happy at the start and end of their lives?

    _____________________________________________________________________________________

2. Where are the scientists in the passage from? 

    _____________________________________________________________________________________

3. When does the unhappiness reach the highest point among men in America, at the age of 40 or about 50?

    _____________________________________________________________________________________

4. What is the good news for a 70-year-old healthy man? 

    _____________________________________________________________________________________

5. How will a teenager feel in his future life according to the passage? 

    _____________________________________________________________________________________

按要求完成下列各图．

（1）如图1是一种门锁把手的示意图，O点是把手的转轴，请画出作用力F的力臂L．

（2）将图2家庭电路中各电路元件正确连入电路．

（3）楼梯照明灯的一种按键开关上常有一个指示灯．在实际使用中发现：当开关闭合时，只有照明灯发光；开关断开时，照明灯熄灭，指示灯会发出微弱光，以便夜间显示开关的位置．根据这种按键开关的控制特性，请在图3中适当位置填上开关S、指示灯L₁和照明灯L₂的符号能正确表示照明灯和这种按键开关内部电路连接方式．

多数泌尿系统结石( )

A．X线平片不显影结石
B．X线平片可以显示结石影
C．两者均可
D．两者均不可

下列属于风邪的致病特点的项目是（）

A.风为阳邪，易伤阳气

B.风性主动

C.风性善行而数变

D.风性重浊

超前钢管的基本要求是什么？