题干

测电笔是用来辨别________的工具,使用时,手应当接触____,当笔尖接触电线时,若氖管发光,表明接触的是____,此时________________之间构成一个回路,____(有/没有)电路通过人体.当测电笔的笔尖接触电线时,____(允许/不允许)用手或身体的其他部分在去接触笔尖.
上一题 下一题 0.0难度 选择题 更新时间:2019-07-04 11:50:16

答案(点此获取答案解析)

火线,零线,笔尾金属体,火线,火线,测电笔,人,大地,有,不允许

同类题1

    Parents often assume that time spent with their kids will gradually decrease in adolescence. But a new study suggests that while teens try to avoid spending a lot of time together with their parents, private parent-child meetings may actually increase in their early adolescent years. And that may raise a teenager's self-esteem (自尊) ansocial confidence, especially if it is time spent with Dad, the researchers added.

    The researchers created a long-termstudy in which they invited families in 16 school districts in central Pennsylvania to participate. In each family, a teenager, a younger sibling, their mother and their father were interviewed at home and then asked about their activities and self-worth five times over a period of seven years.

    The study authors were surprised to discover that when fathers spent more time alone with their teenagers, the kids reported they felt better about themselves. Something about the father's role in the family seemed to improve self-esteem among the teenagers in the study, said study author Susan McHale, a professor of human development at Pennsylvania State University.

  “Time spent with Dad often involves joking, teasing and other playful interactions. Fathers, as compared to mothers, were more involved in leisure activities and had more friend-like interactions with their children, which is crucial for youth social development,” the study showed.

    But Marta Flaum, a psychologist in Chappaqua , New York, said, “How these findings reflect the real world is areal question. The sample in the study is so small and so unrepresentative of more families in the country today that I'm not sure how much we cangeneralizing from it. In my community, in Westchester County, I don't see parents and teenagers spending much time together at all. Parents are often working so hard and have less time to be together with their kids.”

    However, Flaum encourages parents to make time for their kids no matter how much work they have to do. “Research like this reminds us of how important it is. The time we have with themis so short, ” she said.