（6分）．有两个完全相同的带电绝缘金属小球A、B，分别带有电荷量QA=6.4×10-9C，QB=-3.2×10-9C，让两绝缘金属小球接触，在接触过程中，电子如何转移并转移了多少?
3.0×1010个
两球接触后所带电荷量相等且为：
在接触过程中，电子由B球转移到A球，不仅将自身的负电荷全部中和，且电子继续转移，使B球带
的正电，因此共转移电子的电荷量为：
转移的电子数为：
即电子由B向A转移，共转移了3.0×1010个
本题考查电荷守恒定律，首先移动的是电子，对于异种电荷间先中和后平分，由此可求得接触后两球电荷量的大小和正负，从而判断出转移的电子电量，再由一个电子的电量求出电子数
It was the first day of school. I had a new classmate, a little old lady with a warm smile. She said, “Hi, young man! I'm Rose. I’m 87 years old. Can I give you a hug? ” I said , “Of course!” “Why are you in college at such an age?” I asked. She joked, “I’m here to meet a rich husband, get married, have children, and then travel around the world.” “No, seriously,” I asked. “I always dreamed of having a college education. Now I’m getting one!” she told me. After a year, Rose became . She could easily get along well with others wherever she went. She loved to dress up and she enjoyed the attention from others. At the end of the term we invited Rose to at our party. I’ll never forget what she taught us. “We do not stop playing because we are old; we grow old because we stop playing. Here are the secrets of staying young. You have to laugh and find humor every day. You’ve got to have a dream. When you your dreams, you die!” she said. “There is a big between growing old and growing up. Anybody can grow old. That doesn’t take any talent,” she added. “But to grow up, you have to find the chance in change. Have no regrets(遗憾). We usually don’t have regrets for what we did, rather for things we did not do.” Finally we graduated from the college with Rose. One week after graduation, she died peacefully in her sleep. She taught us by example that it’s never too late to be all you can possibly be.
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