太阳能热水器、电热水器、燃气热水器是常见的三种热水器．现需将10kg、20℃的水加热到40℃，不考虑能力转换过程中能量的损失，若用太阳能热水器加热，则水吸收了____J太阳能；若用额定功率为1000W的电热水器正常加热，则需要____分钟；若用燃气热水器加热，则需要完全燃烧____m³的燃气．（水的比热容为4.2×10³J/（kg•℃）．燃气的热值为4.2×10⁷J/m³）

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    In fact, at the time they seemed to be ordinary events, but now everything seems different. I had spent 10 years away from the place where I was born. Even though I made the decision to leave my country by myself, I miss a lot of things now. The person that brought me the happiest memories is my best friend. She is the greatest person in the world, and I am not exaggerating(吹嘘). She is kind, funny, polite, and always willing to listen,  and has been a great friend. I always recall (回想) events from our childhood. I think about the school where we met in the first grade and went on until the 5th grade. I think about the talks we had and the things we did together. If someone wants me to describe our friendship, I'd say we have been close friends for 17 years and we never got angry with each other. It's amazing,  isn't it? I haven't been able to do that with anybody else. Sometimes I even feel guilty(有罪的). I miss her more than my own brothers and sisters. And of course besides those memories, my kids are number one in my life. I have plenty of beautiful memories with them, especially when they were born, which also turned out to be a sad moment for both of them, because they were premature babies(早产儿). Anyone, who has had an experience with a premature baby, can figure out what I mean.