题干

在图所示的电路中,电源电压保持不变.闭合电键S,当滑动变阻器的滑片P向右移动时,不变的是()

A: 电压表V1示数与电压表V2示数的差值

B: 电压表V2示数与电流表A示数的比值

C: 电压表V1示数与电流表A示数的比值

D: 电压表V1和电压表V2示数之差与电流表A示数的比值

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答案(点此获取答案解析)

D

同类题5

阅读下面短文,然后从各题所给的四个选项中选出一个最佳答案。

    My mom keeps asking what's going on at school, if I'm going to audition(试演)for a party, why I didn't try out for the female lead, what my friends are doing, and so on. It's 1 and sometimes it's like she doesn't trust me. How can I get her to 2?-Katie Many teenagers have the same 3 as Katie. They think it difficult to 4well with their parents. However, if you try another way, you can make a 5 . Parents seem to like6about your day. If you don't share or talk7with your parents, they might feel the need to ask you questions. It might seem that they're prying into(打听)your business, but they're probably just trying to keep your relationship8. In fact, parenting experts often9parents to form a good relationship with their kids by asking about what's going on in their lives. Some parents do this better than 10, of course.(And, unfortunately, some parents do ask questions because they don't trust their kids, especially if their kids have been in 11 .So start by trying to give your parents the benefit of the doubt. Maybe they're just trying to stay 12 because they love and care about you. That doesn't make the questions any less annoying, 13. If you're tired of so many questions about your day, 14 the tables – ask your parents questions and use it as a way to practice your good listening skills. 15 tell them about your day before they ask. If you offer more information, conversations with your parents won't have so many questions.