某同学看到一列沿直线行驶的火车，车头冒出的白烟恰好是竖直向上的，则这列火车是向______方向行驶的，其行驶速度是______千米/时．（此时风向是西风，风速是5米/秒）
车头冒出的白烟恰好是竖直向上的，
白烟受到风的作用，风的方向和白烟的方向相反，速度相等，所以白烟的速度为5m/s，方向向西．
火车的运动方向和白烟方向相反，速度相等，所以火车的速度为5m/s，方向向东．
5m/s=18km/h．
故答案为：东；18．
Mary and Donald Smith lived in the same building.Donald 41 a toy company.One day Donald gave Mary. the 4-year-old girl.a new toy.She played with it and said. "This is fun! A few weeks later Donald gave her 42 toy. She played with it and then said."I'm not 43 in this toy. It doesn't work."For years Donald gave Mary new toys. and she gave him very good 44 about the toys. When Mary was 13 years old. Donald showed her a new ball.Mary wanted to 45 the ball with small stones to make it 46 .The company made this change.Mary's idea was a great success! The company sold thousands of the balls. That Christmas. Donald gave Mary an 47 gift.He made her vice-president(副总裁) of the toy company.She made $200,000 a year.Her job was lo see 48 the new toys were fun.She worked 49 three or four hours a day at her job,then she had to do her homework. Today Mary works at a college. The little vice-president with bright ideas helps students think about their 50. 小题1:A.owned B. rioted c.owns D.closes
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