搜题请搜索小程序“爱下问搜题”
问题 选择题

关于牛顿运动定律，以下说法正确的是

A．牛顿通过实验直接证实了物体具有保持匀速运动状态或静止状态的性质，从而发现了牛顿第一定律

B．牛顿第一定律在非惯性系中是不成立的

C．牛顿第一定律是第二定律在合外力为零的条件下的特例

D．作用力和反作用力总是同一性质，它们产生的效果一定相同

答案

答案：B

伽利略利用斜面实验证明了牛顿第一定律，A错；牛顿第一定律的内容是物体在不受外力时保持匀速直线运动或静止状态，不是第二定律在合外力为零的条件下的特例，C错；作用力和反作用力总是同一性质，它们产生的效果不一定相同，D错；

填空题

电子邮件应用程序向邮件服务器传送邮件时使用的协议为 __________________ 。
查看答案
完形填空

第二节：任务型阅读（共3小题，每小题2分，满分6分）

阅读下列材料，然后按要求完成材料后面的三个小题。

Driving Rules in Winter

Winter is dangerous because it’s so difficult to know what is going to happen and accidents take place so easily. Fog(雾) can be waiting to meet you over the top of a hill. Ice might be hiding under the melting snow, waiting ahead to send you off the road. The car coming to you may suddenly slip(滑)  across the road.

Rule Number One for driving on icy roads is to drive smoothly(平稳地). Sudden movements can make a car very difficult to control. So very time you either start or stop your car, increase or reduce your speed, you must be as gentle and slow as possible. Suppose you are driving with full cup of hot coffee on the seat next to you. Drive so that you wouldn’t spill(溅) it.

Rule Number Two is to pay attention to what might happen. The more ice there is, the further down the road you have to look. Test how long it takes to gently stop your car. Remember that you may be driving more quickly than you think. Generally, allow twice of your usual stopping distance when the road is wet, three times this distance on snow and even more on ice. Try to stay in control of your car at all times and you will not get into trouble.

请根据阅读材料补全以下语句信息。（48-49题，每空一词，共4分）

48. Winter is dangerous for drivers because there may be ____  or  ____ on the road.

49. In order to drive smoothly, you must avoid _____ ______.

根据阅读材料的描述用英语完成以下任务：（共2分）

50. The passage mainly tells us ______________________________________.
查看答案