问题
连词成句
连词成句。
1. cats, The, can, the, catch, mice (.)
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2. went, She, to, the, yesterday, library (.)
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3. usually, homework, does, Kangkang, in, the, his, evening (.)
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4. is, He, chess, playing, with, John (.)
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答案
1. The cats can catch the mice.
2. She went to the library yesterday.
3. Kangkang usually does his homework in the evening.
4. He is playing chess with John.
聚变成氦核
同时放出2个正电子
和2个中微子
，请写出该氢核聚变反应的方程，并计算一次反应释放的能量。