[物理--物理3-4] 如图为一列横波在某时刻的波动图象，此波中d质点到达波谷的 发布时间：2017-04-25 09:34 │ 来源：www.tikuol.com 题型：问答题 问题： [物理--物理3-4]如图为一列横波在某时刻的波动图象，此波中d质点到达波谷的时间比e质点早0.05s．求：①此列波的传播方向和波速是多大？②1.0s内b质点通过的路程是多少？
题型：问答题 阅读理解。 As we know, some children live in the countryside, and some live in the city. Their lives are a little different, but they also have many of the same dreams.In the countrysideIn the cityWays of going to schoolOn foot or by bikeBy bus or carTeaching toolsRecorders (录音机) and radiosDVD, TVs, recorders, radios,loud-speakers, CAIEyesightLess than 45% are near-sighted (近视)About 75% are near-sightedAfter-class activitiesPlaying with ballsEnglish corners and other school clubsHomeworkHomework can usually be finished at schoolHomework never endsChores (杂事) to doWashing, cleaning, farming, looking after younger sisters or brothers, cookingUsually no chores FamilyBig familiesSmall familiesDream jobsTeachers, drivers, scientists, nurses…Scientists, doctors, computerprogrammers, managers … 1. The survey was done among the ________ between the countryside and the city.[ ]A. parents B. students C. teachers D. drivers2. The children in the city usually do ________ according to the survey.[ ]A. cooking B. cleaning C. washing D. no housework3. About ________ of children in the countryside have good eyesight, while ________ of children in the city have good eyesight. [ ]A. 55%; 25% B. 45%; 25% C. 45%; 75% D. 55%; 75%4. Which is NOT mentioned in the survey?[ ]A. Homework. B. Subjects. C. Dream jobs. D. After-class activities.5. Which of the following is RIGHT according to the survey?[ ]A. A classroom in the countryside often has TV sets. B. Children in the countryside often join the school clubs. C. Children in the city often have much homework to do. D. Children in the city often have big families. 查看答案
题型：问答题 根据《工程建设项目施工招标投标办法》（国家八部委局第30号令），工程施工招标投标活动应当遵循的原则是（）。A.公平、公正、公开、实事求是B.公开、公平、公正、诚实信用C.公平、公正、科学、择优D.公平、公正、公开、科学、择优 查看答案
