问题 选择题

为了研究超重与失重现象,某同学把一体重计放在电梯的地板上,他站在体重计上随电梯运动并观察体重计示数的变化情况.下表记录了几个特定时刻体重计的示数(表内各时刻不分先后顺序),若已知t0时刻电梯静止,则(  )

时刻t0t1t2t3
体重计示数(kg)50.055.045.050.0

A.t1和t2时刻该同学的质量和重力均不相同

B.t1和t2时刻该同学的质量相同,但所受重力不同

C.t3时刻电梯可能向上运动

D.t1和t2时刻电梯运动的加速度方向相反,运动方向也相反

答案

A、t1和t2时刻物体的质量并没有发生变化,所受重力也没有发生了变化.故AB错误.

C、t3时刻物体处于平衡状态,可能静止,也可能向上匀速运动.故C正确.

D、根据表格读数分析,t1时刻物体处于超重状态,根据牛顿第二定律分析得知,电梯的加速度方向向上.t2时刻物体处于失重状态,电梯的加速度方向向下,两个时刻加速度方向相反.但运动方向都可能向上或向下,不一定相反,故D错误.

故选C.

完形填空

阅读下面短文并回答问题(请注意问题后的词数要求 )

[1] You can never get to peace and security without first knowing all of the good things in your life. So you need to learn how to appreciate your life and here are some simple steps you can take to achieve this goal.

Work hard to have an attitude of gratitude.

[2] As you learn to appreciate the small things in your life, you’ll find a sense of happiness. You’ll also find it easier to appreciate the big things in your life, which will help you appreciate your life as a whole.

[3] To begin with, find five things to be grateful for each day. Call this your “Gratitude List,” and write it down before bedtime. At first,      to find even just five things to be grateful for. That’s okay. You won’t learn how to appreciate your life over night, just like you didn’t become dissatisfied over night either. List small things, and go from there. The longer you keep a “Gratitude List,” the easier it will be to find things to put on it. Soon you’ll be able to list more things than you thought!

Learn to appreciate others.

[4] Take note when someone does something nice for you. If anyone does a job that’s normally yours, stop and thank them sincerely. Value the moment, and look for other opportunities to find the good in others. This will help you appreciate the people around you, who are also part of your life.

Appreciate yourself.

[5] This can be extremely hard, especially with all the criticism we hear from others. Appreciation also includes respect and you can’t appreciate or truly enjoy your life if you don’t respect yourself . So, think of one small thing you can appreciate about yourself every day, and take the time to really enjoy it. Be thankful for it, and know you’re learning how to really appreciate your life.

[6] It takes 30 fays of doing something before it becomes a habit. But after this, keeping a “Gratitude List,” appreciating others, and admiring yourself will become second nature to you. In no time, you’ll realize you know how to appreciate your life.

小题1:What is the main idea of the text?(no more than 10 words)

                                                                           

小题2:Complete the following statement with words from Paragraph 2.(no more than 5 words)

                                                                           

小题3:How can we learn to appreciate others around us?(no more than 10 words)

                                                                           

小题4:Fill in the blank in Paragraph 3 with proper words.(no more than 4 words)

                                                                           

小题5:What does the word “it”(Line 4, Paragraph 5 ) probably refer to?(no more than 4 words)

                                                                           

单项选择题