当前，能源问题已引起世界各国的高度重视，21世纪核能将成为世界的主要能源之一．我国现已成为第二能源消耗大国，并正在大力开发利用核能，那么，在世界和平利用核能的过程中，人类利用的是原子核____变时释放的能量．

    One night, I wondered what it would be like if I only asked questions. I decided that no matter what anyone said to me the next day, I would reply only with 1.
    I loved to read about scientists and their discoveries, and I knew that scientists always started their research with a question. I hoped that I could become a scientist. Maybe by asking questions, I could train my mind to be 2.
I survived the morning easily. “Is there any egg?” I answered when my mother asked what I wanted for breakfast. “Is this seat taken?” I asked when my friend Mike asked where he was going to 3 on the bus.
    In the classroom, Mr. Black spoke slowly and clearly while I listened carefully. The problem had been part of my homework the night before. I wrote the answer on the board, “Could the answer be 361?”
Mr. Black smiled and nodded. I thought,“How did I 4 to get through that?” I almost laughed because asking questions really was starting to become a 5.
    I thought I had made it safely through the whole day, 6 what I had come to consider my experiment blew up at the dinner table when my dad asked me about my day. “What do I always do?” I replied.
My parents looked at each other. My father 7 again. “Well, I hope you went to school,” he said.
    “Uhhh … why would you think otherwise?” I asked. My parents exchanged another 8  and were becoming annoyed.
    “Do you think questions are a good way to train your mind to be active?” I asked.
    “It 9 the question,” said my father. “Some questions are asked for 10 information. Those are good mind-training questions. Sometimes, people use questions to get the other person to say something. Sometimes people ask questions to get someone to agree with them. Those questions don't really achieve anything.”
    “I guess my experiment didn't work,” I said, and I told my father about my 11.
    “I think it worked 12!” my father said. “You made a discovery, didn't you? What matters is that you have put your idea into practice.”                             

    Surfing the Internet for fun will make you a better employee, according to an Australian study.

    The University of Melbourne study shows that people who use the Internet for their own reasons at work are about 9 percent more productive(具有创造性的) than those who do not. Study author Brent Coker said, “Surfing the Internet at times helps increase workers' attention.”

    “People need to relax for a bit to get back their attention,” Coker said on the university's website. “Having a short break, such as a quick surfing of the Internet, helps the mind to rest itself, leading to a higher total Internet attention for a day's work, and as a result, increases productivity (生产效率),” he said.

    According to the study of 300 workers, 70 percent of people who use the Internet at work surf the Internet for their own reasons during office hours. Among the most popular surfing activities are searching for information about products, reading online news, playing online games and watching videos. “Firms spend a lot of money on software to block their workers from watching videos, using social networking sites or shopping online,” said Coker. “That's not always a good idea.”

    However, Coker said the study looked at people who surfed the Internet in moderation(适度), or were on the Internet for less than 20 percent of their total time in the office. “Those who spend too much time surfing the Internet will have a lower productivity than those without.” he said.