题目

下列做法正确的是A.检验装置的气密性时，先用手紧贴容器外壁，再将导管一端浸入水中B.称量时，要把称量物放在左盘，砝码放在右盘C.用镊子夹持蒸发皿D.过滤时为加快过滤速率，要用玻璃棒不断搅拌漏斗里的液体 答案：【答案】B【解析】A、检验装置的气密性时，先将导管一端浸入水中，再用手紧贴容器外壁，选项A错误；B、称量时，要将称量物放在左盘，砝码放在右盘，选项B正确；C、用坩埚钳夹持蒸发皿，选项C错误；D、过滤时用玻璃棒不断搅拌漏斗里的液体，易使滤纸破损，选项D错误。故选B。What do you think Americans in the early twentieth century (1900--1925) did on weekends? What do they do on weekends now?Then Once upon a time, people spent lots of time at home on weekends. Then new inventions changed the weekends. People used electric（电动的） streetcars to travel in cities. On weekends, they rode the streetcars to parks. Young people liked roller coasters.（过山车）The first movie lasted only one minute. Soon movies lasted longer. In the 1920s, movie theaters sold millions of tickets each week. In 1927, movies eventually（最终） had sound. Sometimes, people stayed at home instead, and listened to another new invention—radio. People in cities worked indoors during the week, so they wanted to be outdoors on weekends. Bicycling became a popular activity.Now With more time, money and inventions, people have many more choices.They can visit large parks like Disney World and ride modern roller coaster that go higher and faster than ever before. They can choose from lots of different movies at a multiplex (a building with many movie theaters) or watch a video at home. Many people jog （慢跑）, bicycle, work out at the gym, or play sports. Others turn on their TV and watch sports.小题1:Before the early twentieth century, Americans used to spend their weekends       .A．at homeB．in the theaterC．outdoorsD．in the park小题2:What do you know about the first movie ?A．It had no soundB．It got longerC．It sold wellD．It lasted minutes小题3:The best title of the text is     .A．Many More ChoicesB．The New Invention C．The Popular ActivitiesD．The Changing Weekend