题目

某同学学习了热学的有关知识后，知道水的比热容是c水=4.2×103J/（kg•℃），他想估算一下自己家每天烧水、做饭需要的热量，于是他仔细记录了每一天烧水、煮饭、炒菜需要的时间，并折算成烧水时间，相当于每天将30kg、20℃的水烧开（在一标准大气压下）． （1）该同学家每天烧水、做饭需要多少热量？ （2）如果普通煤的热值为3×107J/kg，从理论上讲，该同学家每天做饭需要多少kg煤？ （3）该同学家实际每天需要烧煤2kg，由此算出他家煤炉的效率Sometimes willpower is a lot like the television remote control — hard to find just when you want it most. Whether you’re trying to lose weight, stop smoking, get to the gym regularly，developing your sense of willpower is an important part of changing any behavior. ___1.__. But there are ways to increase your willpower. Don’t try to change your economic situation, win a promotion and lose weight all on the same morning. Establish one clear, specific goal and make a realistic plan for achieving it. Extra willpower sometimes requires extra energy, so don’t stretch yourself too thin. __2.__. Whatever your goal is, don’t expect to achieve it overnight. __3.__ . If you are trying to kick a caffeine habit, start by replacing your morning cup of coffee with a glass of water, instead of vowing never to drink coffee again. Congratulate yourself on the small achievements that will pave the way toward a larger one. These successes help your willpower grow. __4.__. Ask friends, family or colleagues for assistance and tell them exactly how they can help. If your credit card bills have increased sharply, for instance, let friends know that you are cutting back on expenses. Suggest having a common dinner instead of meeting at an expensive restaurant. Find a support group or organization related to your goal and attend their meetings. You can get valuable advice, understanding and information. If possible, change your environment to encourage positive behavior. Want to get in shape? Keep an extra set of workout clothes in your office as a reminder to stop by the gym on the way home. Quitting smoking? __5.__. A．Change your environment to change your life B．Real success takes time. C．Avoid bars or restaurants where you might be attracted to light up. D．Changing your behavior requires more than willpower. E. Improve your willpower by a support network. F. Breaking a bad habit or forming a new and healthy one can be difficult. G. Focus on one goal at a time.