题干

如图所示,把一根塑料绳的一端扎紧,从另一端撕开许多细丝,用干燥的手从上向下捋几下,发现细丝张开了.下列分析正确的是   (    )

A:细丝张开的原因是带了异种电荷互相吸引

B:细丝张开的原因与验电器的工作原理相同

C:细丝带了电是通过摩擦的方法创造了电荷

D:细丝带上了电的实质是分子在物体间的转移

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B

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    Ask any kid, and you'll likely hear that time spent with friends is the coolest and most important part of the school day. Educators, as well, acknowledge that making friends is one of the most valuable things children do as they learn and grow. But many parents are perplexed by their children's social lives, wondering how to help their kids cope with the challenges, heartbreaks, and the joys of making friends, losing them, and making friends again.

    “Friendships help children gradually learn to be independent, contributing members of a community and it's just as important as their academic growth” notes Diane Levin, Ph.D., author of “Remote Control Childhood.” However, it's a slow process. There are many social skills to learn, which advance with age and experience, trial and error, and experiencing the satisfaction that comes from contributing to an ongoing friendship.”

    “Friendship starts as soon as children can crawl off their parents' laps over to another child,” adds Michael Thompson, Ph.D., co-author of her life with you to her life with her friends. but who their friends are, how they interact with them, and how popular they are, is something parents have only limited control over.”

    Experts on children's behavior say that problems like jealousies, breakups, bullying and teasing account for a big part of what parents, kids and teachers talk about, and what parents worry about.

    Get insights into how children's friendships develop and how parents can help, if needed, and find ways to determine if your child is at risk for serious social problems or simply suffering from real (but common) social challenges.