题目

某物理兴趣小组做了如图所示的实验来探究浮力的大小： (1)铜块浸没在盐水中时受到的浮力是____N； (2)由①③④⑤四个步骤可知，发现浮力的大小有时与深度有关，有时又与深度无关，对此正确的解释是浮力的大小与_____有关； (3)比较①④⑦三幅图可得出的结论是_____； (4)要探究物体所受的浮力大小是否与物体的密度有关，应选取图中_____（选填图中数字代号）步骤进行对比分析； (5)探究完浮力大小的影响因素后，同学们想进一步探究浮力的大小与 完形填空：通读短文，掌握大意，选出一个最佳答案。  The Internet has become part of teenage life. A new report on 3,375 students aged from 10 to 18 in seven Chinese cities found that 38% of them think they use the Internet often.       While most of them get   1   information and use the Internet to help themselves in their studies, but some are not using it in a good way. Many play online games too much. A few   2   visit websites they should not look at. Hong Ying, a teacher from Beijing Yinghua Middle School warns that bad things can happen if young people spend   3  time on the Internet. She had a student who  4  be good at study. But then he started visiting erotic(色情的) websites. He went mad, cheated a girl and was taken by  5__.        In order to help young people use the Internet in a good way, a   6  on good Internet behavior has started to be used in some Shanghai middle schools this term. The book uses real examples to teach students all about good ways of using the Internet. The book gives useful_7 , such as it’s good to read news or to find helpful information to study.       Some students also make online friends. But if you are meeting a friend offline,   8__   your parents know. Teachers and parents all think the book is a very good one.   Hong said the book would be a guide for teens using the Internet. She believes it will keep students __9  bad sites.     “Many students are using the Internet without guidance(指导) from their parents,” she said. “The book will   10  students how to be a good person in the online world.” Choose the best word or phrase and complete the passage. (   )1. A. bad         B. interesting     C. useful      D. exciting (   )2. A. even        B. never         C. much       D. really (   )3. A. little        B. a little         C. much too   D. too much (   )4. A. is used to 　 B. are used to     C. used to      D. uses to (   )5. A. his teacher   B. the headmaster  C. his parents  D. the police (   )6. A. CD         B. book         C. TV play     D. movie (   )7. A. languages    B. pictures       C. songs      D. advice (   )8. A. ask         B. prevent       C. make sure    D. find (   )9. A. away from   B. with          C. in          D. into (   )10. A. make      B. talk            C. teach      D. learn from