题目

暖水瓶的瓶胆夹壁中是真空，小明想利用它来探究真空能否传声。他把音乐贺卡里的电子发生器放入瓶中，根据听到的声音进行判断。在他设计的下列几组比较方案中最合理的是（） A . 塞上瓶塞和不塞瓶塞进行比较 B . 把瓶胆放在近处和远处进行比较 C . 用一个完好的和一个已经漏气的瓶胆进行比较 D . 将音量大小不同的芯片先后放入瓶胆中进行比较Boys need friends, suffer when they don’t believe they have any, and worry over the ups and downs of relationships. Many adults believe that somehow boys need friends less than girls do, in truth, though, no boy is an island; boys value their friends throughout childhood and adolescence and are happier and healthier when they have solid relationships with peers. Despite the common belief that girls are better at relationships, most boys consider their friends a very important part of their lives and boys may actually be better at keeping friendships than girls are. A recent study of 10 to 15-year-old boys and girls found that girls’ friendships are actually more fragile（脆弱）. Girls tend to say and do hurtful things to each other more frequently than boys, and girls are more hurt by the end of a friendship. Boys are the living definition of the phrase “peer group”; they love games with rules, competition, and doing things together. Boys seem to enjoy, even need the opportunity to test themselves against others, and many lasting friendships begin in karate（空手道）class or on the basketball court. Competence and skill are widely respected; being picked last for a team or left out altogether is an experience that can haunt（萦绕心头）a boy for years. As boys mature（成熟）, the friendship becomes even more important, and it frequently widens to include girls. During the teen years, friends can become the most important part of a boy’s life — and a part in which his parents are not included. The confusion of being a teenager leads boys to form close bonds with friends. There is the sense for many boys that a friend is someone who is “always there for me”, someone he can trust. They may be partners in crime or partners in study, but the friendship of adolescent boys can run surprisingly deep. 73. The common belief of adults is that boys _________ . A. don’t care about others as much as girls      B. don’t value friendship as much as girls C. have the same friendship as girls                  D. have healthier friendship than girls 74. According to the text, _________. A. boys usually build friendship by playing competitive games B. boys like to have small groups of friends C. boys’ friendship seldom result in anyone being hurt D. boys’ friendship can hardly end in failure 75. The author mentions the study in Para. 2 to prove _________. A. girls value relationships more than boys   B. most boys consider their friends very important C. boys may be better at keeping friendship than girls   D. boys may be more active in a friendship 76. As a boy gets older, he tends to __________. A. widen his circle of friends to include his parents.  B. shift his focus from his friends to himself. C. be confused about what a friendship is.       D. leave his parents out of his friends.