屏蔽效应

下列细菌中属于有益菌的是()

A．蜡样芽胞杆菌

B．铜绿假单胞菌

C．大肠埃希菌

D．双歧杆菌

E．绿色链球菌

Most people want to be happy, but few know how to find happiness. Money and success alone do not bring lasting happiness. Aristotle, a Greek thinker, said, “Happiness depends upon ourselves.” In other words, we make our own happiness. Here are a few suggestions to help you be happier.

The first secret of happiness is to enjoy the simple things in life. Too often, we spend so much time thinking about the future —for example, getting into college or getting a good job —that we fail to enjoy the present. You should enjoy life’s simple pleasures, such as reading a good book, listening to your favorite music, or spending time with close friends. People who have several close friends often live happier and healthier lives.

Another secret to living a happy life is to be active, and have hobbies where you forget your problems and time. Many people experience this dancing, or playing a sport, such as swimming. You can forget about your problems, and only think about the activity. Finally, many people find happiness in helping others. Studies show that people feel good when they spend their time helping others. If you want to feel happier, do good things for someone. You can help a friend with his or her studies, go shopping to buy food for an elderly person, or simply help out around the house by washing the dishes.

小题1: The best title（标题）of the passage is ________.

A．Money Makes You Happy

B．The Secrets of Happiness

C．Ideas for Helping Other People to Be Happy

D．Good Friends Make You Happy小题2:The second paragraph tells us that ________.

A．the more friends you have, the happier you will be

B．we shouldn’t think about our future

C．happiness is to enjoy the simple things in life.

D．some people fail to live a happy life小题3:The passage gives us ________ pieces of advice on happiness.

A．one

B．two

C．three

D．four小题4:The writer thinks that ________.

A．everyone knows how to live a happier life

B．it’s wrong to spend time on work

C．hobbies take up too much time

D．doing good things for someone can make you happier小题5:Which of the following is not mentioned in the passage?

A．Reading a good book.

B．Traveling to a foreign country.

C．Playing a sport.

D．Spending time with close friends.

长时间运动时，一般先利用的能源为（）。

A.血中的糖

B.血中的脂肪酸

C.机体的蛋白质

D.人体多余的脂肪

E.肌肉的能源

中国生理学家（）的研究表明，美洲袋鼠间脑的室旁核具有（）的特征

平板式筏形基础的板的最小厚度不应小于（）mm。（）

A.700

B.600

C.500

D.400