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问题 选择题

一个带电小球，用细绳悬在水平方向的匀强电场中，当小球静止后把悬线烧断，小球将做（   ）

A．自由落体运动

B．匀变速曲线运动

C．沿悬线的延长线的匀加速直线运动

D．变加速直线运动

答案

答案：C

小球受力平衡，当去掉一个力后，其余各力的合力与该力等大反向，即电场力和重力的合力沿细绳方向，因此，把悬线烧断后，小球将沿悬线的延长线做匀加速直线运动，正确选项为C.

选择题

马克思主义的理论来源是

A．法国唯物主义、英国经验主义、德国理性主义

B．细胞学说、能量守恒定律、生物进化论

C．德国古典哲学、英国古典政治经济学、英法空想社会主义

D．法国历史哲学、英国科学主义、欧洲人文主义
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填空题

Happiness Secrets for Tough Times


1. You don’t need an expert to tell you that relationships are critical to happiness. Not being the bread-winner anymore or not being able to fulfill your kid’s needs can weigh down hard on your family life. But the trick is to stop feeling guilty and focus on nurturing your loved ones. "I was at a psychology conference where an expert was talking about the effects of this economy on families and how parents can’t afford to buy their kids luxuries like toys anymore," says Sonja Lyubomirsky, author of The How of Happiness: A Scientific Approach to Getting the Life You Want. "But what they don’t realize is that kids don’t care about toys-what they care about is parents being grumpy and taking it out on them."
2. Now more than ever we need each other to survive. Lyubomirsky found that doing good things for friends, family, or strangers can make you happier. Think of practical, everyday gestures that can make someone’s life a little bit easier. For example, Lyubomirsky says, "Maybe now many of us can’t afford to take a cab to the airport, so offer to give a friend a ride."
3. "You could spend a lot of time ruminating," says Lyubomirsky. "But that just makes you feel even more pessimistic, more out of control, and affects your self esteem. Your relationships will suffer and your job performance will suffer." Get rid of pessimism. One of the most effective ways to cope when things are difficult is to adopt a positive thinking strategy. "What can I learn from this Times are tough, I’ve been furloughed at work, but I can spend more time with the kids, adopt a new hobby, or learn a new set of skills."
4. "if you find a happy person you will find a project," says Lyubomirsky. "Happy people all have goals they care about." Commit yourself to a project — whether it is a business you want to start or a dance you want to learn. But it’s also important to remember to be flexible in these times. Don’t get frustrated if circumstances are stopping you from meeting your goals. Adopt and change! "If your spouse has lost their job you might have to change your goal," says Lyubomirsky. "Or you might have to learn a whole new skill for a new job."
5. When times are tough, it’s easy to get skip your regular workouts in favor of moping in front of the TV and eating a bag of chips. Your thinking is "I have more important things to worry about right now than looking good." But carve out a small part of your day to give your body some TLC. It will go a long way in boosting your happiness. "Even if you can’t afford to go to the gym," Lyubomirsky says, "take time out to exercise at home or meditate."
A. Have a goal and be flexible
B. Find a new friend
C. Avoid over-thinking
D. Do some physical exercise
E. Help others
F. Focus on your relationships
G. Try to fulfill your kid’s needs

Paragraph 2 ______
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