搜题请搜索小程序“爱下问搜题”
问题 选择题

如图所示，物体A、B之间用轻直杆连接，重力分别为2N、4N，A用轻弹簧悬挂在顶板上，弹簧的弹力为3N，则轻杆对B的作用力以及B对地面的压力的可能值分别为

A．1N，6N               B．2N，5N

C．5N，9N               D．2N，3N

答案

答案：C

弹簧的弹力为3N，弹簧可能处于伸长状态也可能处于压缩状态，当弹簧处于伸长状态时，以AB为整体，受地面的支持力和弹簧拉力，还有重力，地面的支持力为3N，以B为研究对象，受地面的支持力、重力和杆的弹力，设杆的弹力向上有：F+FN=mg，F=1N，用同样的方法分析当弹簧是压缩状态的情况，可知C对

单项选择题 A型题

遗尿是指已达到控制排尿的年龄而入睡后仍有不自主排尿，一般指年龄不超过几岁（）

A.2

B.3

C.4

D.5

E.6
查看答案
单项选择题

Bringing More Humor and Laughter into Our Lives


在生活中带进更多的幽默和笑声


The sound of roaring laughter is far more contagious than any cough, sniffle, or sneeze. Humor and laughter can cause a domino effect of joy and amusement, as well as set off a number of positive physical effects. Humor and laughter strengthen our immune systems and help us recover from illness, as well as bring joy into our lives. The question is: how do we gain access to this priceless medicine
A good hearty laugh can help
reduce stress
lower blood pressure
elevate mood
boost immune system
improve brain functioning
protect the heart
connect you to others
foster instant relaxation
make you feel good
Humor is a powerful emotional medicine that can lower stress, dissolve anger and unite families in troubled times. Mood is elevated by striving to find humor in difficult and frustrating situations. Laugh at yourselves and the situation helps reveal that small things are not the earth- shaking events they sometimes seem to be. Looking at a problem from a different perspective can make it seem less formidable and provide opportunities for greater objectivity and insight. Humor also helps us avoid loneliness by connecting with others who are attracted to genuine cheerfulness. And the good feeling that we get when we laugh can remain with us as an internal experience even after the laughter subsides.
Mental health professionals point out that humor can also teach perspective by helping patients to see reality rather than the distortion that supports their distress. Humor shifts the ways in which we think, and distress is greatly associated with the way we think. It is not situations that generate our stress, but it is the meaning we place on the situations. Humor adjusts the meaning of an event so that it is not so overwhelming.
Here are some additional things we can do to improve our mood, enjoyment of life and mental health.
Attempt to laugh at situations rather than bemoan them—this helps improve our disposition and the disposition of those around us.
Use cathartic laughter to release pent-up feelings of anger and frustration in socially acceptable ways.
Laugh as a means of reducing tension because laughter is often followed by a state of relaxation.
Lower anxiety by visualizing a humorous situation to replace the view of an anxiety-producing situation
Our work, marriage and family all need humor, celebrations, play and ritual as much as record-keeping and problem-solving. We should ask the questions "Do we laugh together" as well as "Can we get through this hardship together" Humor binds us together, lightens our burdens and helps us keep things in perspective. One of the things that saps our energy is the time, focus and effort we put into coping with life’s problems including each other’s limitations. Our families, our friends and our neighbors are not perfect and neither are our marriages, our kids or our in-laws. When we laugh together, it can bind us closer together instead of pulling us apart.
Remember that even in the most difficult of times, a laugh, or even simply a smile, can go a long way in helping us feel better.
Laughter is a birthright, a natural part of life. The part of the brain that connects to and facilitates laughter is among the first parts of the nervous system to come on line after birth. Infants begin smiling during the first weeks of life and laugh out loud within months of being born. Even if you did not grow up in a household where laughter was a common sound, you can learn to laugh at any stage of life.

Which of the following statements is NOT right

A．Laughter is a natural part of life.
B．Human beings are not born to be able to laugh.
C．Human beings can learn to laugh at any time of life.
D．Laughter is a kind of medicine, so to speak.
查看答案