题目

如图所示是一种通过测量电容器电容的变化，检测液面高低的仪器原理图，电容器的两个电极分别用导线接到指示器上，指示器可显示出电容的大小，下列关于该仪器的说法中正确的是（ ）A.金属芯线粗细决定电容的大小B.芯柱外套的绝缘管越厚，该电容器的电容越大C.该仪器中电容的两个电极分别是芯柱和电介质D.指示器显示出电容增大了，则电容器中液面升高了阅读下面短文，根据短文大意和语境选择方框内的单词，并用其正确的形式填入空白处，使补全后的短文意思通顺，语法正确，结构完整。send     expensive    waste     problem    coolDear headmaster,I’m a student of Grade 9. I want to tell you something. In our school, many students have mobile phones. They think it’s   1   to have a mobile phone. Yes, the phones let students talk with their parents and friends at any time. But I don’t think it’s good for students to use them at school. Many students spend lots of time in  2   messages by mobile phone, some students even use them to play games in class or cheat (作弊) in the exams. Some students always hope to buy the new or   3   mobile phones and this will   4   theirparents’ money. And my father tells me that most mobile phones can cause (引起)many health   5   . Could you do something to stop it?Yours, Sophia