题目

小明同学将一小石子以一定速度竖直向上抛出，2s后又在原地接住石子，若不计空气阻力，则石子上抛的最大高度约为（ ） A.5m B.10m C.15m D.20m 答案：【答案】A【解析】小石子做竖直上抛运动，上升和下降过程具有对称性，则知下降的时间为：石子上抛的最大高度为故A正确。For Chinese students the end of their senior year is filled with studying and stress as they prepare for the college entrance exams in June．But for American high school seniors the experience couldn't be more different．The end of senior year is a celebration of their time in high school and involves parties, games and fun． Senioritis is a commonly used expression．It means seniors have a disease which makes them unable to do work．This starts in April when seniors find out whether they have been accepted to university． Unwilling to do school work, seniors have plenty of other activities to focus on． Many schools have a "Senior Show", in which only seniors are allowed to perform．Some seniors sing or dance but many of them perform skits （滑稽短剧）, where they make fun of their favorite teachers or their friends．For example, a group of boys may dress up and imitate a group of their girl friends．It is all very light-hearted． The "Senior Show" is usually a part of Senior Week, which is a week specifically dedicated（专用的）to seniors．During this week, seniors usually get academic or athletic awards they have won over their high school careers．The seniors also vote for one of their male and female classmates who they believe is the best-looking or funniest or most involved, etc．These are then published in the yearbook． The yearbook is an important part of high school for seniors．It is usually dedicated to them and has all their pictures and some words from them in it．Then seniors go around and get it signed by their friends so they can always remember their time together． Of course during all of this time, seniors are preparing for the Senior Prom, which is an important moment in American culture．It is the most important dance in a young American's life． The end of senior year is a truly special and wonderful time for American students．It's something they will remember for the rest of their lives． 1．Which of the following is the closest in meaning to the underlined sentence in paragraph 1?        A．For American high school seniors, things are quite different．        B．It doesn't make difference at the end of the senior year．        C．For American high school seniors, it is the best time of the year．        D．It is the period filled with stress and workload． 2．What activities that seniors would like to do according to the passage?         A．School work                                        B．Voting for the film star        C．Singing or dance contests                     D．Senior Show and Senior Prom 3．What will most probably be talked about in the next paragraph of the passage?         A．Activities on the sports field．        B．The graduation ceremony where they receive their high school diploma．        C．Their favorite film stars．        D．The health of seniors．