问题 计算题

从今年4月18日零时起,我国铁路第六次大提速全面启动.一些路段的动车组列车运行速度可达200km/h以上(如图所示),为加快我国的经济建设和人们出行的便利提供了有力的保障,但同时我们也要注意一些相关的安全问题.请回答下列相关问题:

(1)若列车以200km/h的速度行驶200m,只需________秒即可呼啸而至,因此,心存饶幸,强行穿越铁路是非常危险的.

(2)专家指出,以200km/h的速度行驶的列车经过时,车旁的风速相当于7级的大风,路旁行人稍不留神,极有可能被卷入车底.这里所隐含的一条重要物理规律是________.

答案

⑴ 3.6

⑵ 气流速度大的地方压强小

阅读理解

阅读理解。

      Mama and Daddy loved having the family together on Christmas. They spent days making candy and

cookies, preparing gifts and decorating.

      Forty-four years together made them a great team. But with Mama's unexpected death in the spring,

we now faced our first Christmas without her. The holidays would be especially hard for Daddy. We tried

to comfort him. We would all be with him on Christmas as usual.

      On Christmas Eve a small snow turned to a heavy one, covering our yard and 150-foot driveway, as

well as the access road (干道的支路). We started cleaning, but the snow was falling faster than we could

keep up. The weatherman predicted the storm would continue through the night. Church services were also

canceled. "We'll be there as soon as possible in the morning," I told Daddy on the phone. But inside I wondered

how. 

      Early Christmas morning we began digging through stomach-high snow. We finished the driveway, but

seeing the mountains of snow on the access road, we admitted failure. As I stared at the access road, I heard

the sound of a snowblower. Lord, please help us get to Daddy today, I prayed.

      The sound of the snowblower grew louder. I looked up. There, coming straight toward us was a big

yellow machine with a huge plow (犁) effortlessly clearing a path through the snow-packed road. I stared in

disbelief. Never in our 18 years here had the snow been plowed on this road.

      The driver of the snowblower sat up straight at the wheel and was warmly dressed, collar (衣领) up, cap

down-and wings beneath his coat, I'm sure.

1. We learn from the passage that the author's parents _____. [ ]

A. separated a year ago

B. were married for forty-four years

C. like spending holidays very much

D. have prepared for this Christmas for days

2. The author started to clean the snow in order to _____. [ ]

A. go to church

B. have a clean driveway

C. go to please his father

D. send his children to school

3. Before the snowblower arrived, the author had _____. [ ]

A. decided to give up

B. stopped to have a rest

C. finished the access road

D. cleaned the snow mountains

4. In the author's eyes, the driver of the snowblower was a(n) _____. [ ]

A. angel

B. father

C. ordinary cleaner

D. hard worker

单项选择题