问题 选择题

甲、乙两物体同时同地同方向开始做匀速直线运动,甲的速度大于乙的速度,它们的s-t图象为如图所示的a、b、c三条图线中的两条,运动5秒甲、乙间的距离大于2米,则

A.甲的s-t图象一定为图线a

B.甲的s-t图象可能为图线b

C.乙的s-t图象一定为图线c

D.乙的s-t图象可能为图线a

答案

答案:A

题目分析:s-t图象中每一点的坐标表示该时刻物体的位置,倾斜的直线说明物体做匀速直线运动,其斜率表示速度。与纵坐标的交点不同说明初始位置不同。根据已知,甲乙两物体在同一直线上向同一方向做匀速直线运动,所以图象是倾斜的直线而且倾斜方向相同,由因甲的速度大于乙的速度,所以甲的倾斜度要比乙的倾斜度大。又因为初始时刻乙在甲的前面,所以与纵坐标的交点应乙在上面。

故选A。

点评:本题是位移-时间图象的应用,能根据图象读取信息,要明确斜率和坐标轴交点的含义,属于基础题。

填空题
阅读理解

阅读理解。

     After an earthquake most survivors can be expected to recover over time, particularly with the

support of family and friends. Some families will be able to return to their normal life quickly, while

others will have to contend with the destruction of their homes, medical problems, and injury to family

members. Children especially will need time to recover from the loss of a loved one or a pet or from the

closing down of their schools.

     Children often turn to adults for information, comfort and help. Parents should try to remain calm,

answer children's questions honestly and remain understanding when they see changes in their children's

behavior.

     Children react differently to an earthquake depending on their ages, developmental levels and former

experiences. Some will respond by withdrawing (不与人交往), while others will have angry outbursts

(爆发). Parents should remain sensitive to each child's reactions. Parents should spend time talking to

their children, letting them know that it's OK to ask questions and to share their worries. Although it may

be hard to find time to have these talks, parents can use regular family mealtimes or bedtimes for them.

They should answer questions briefly and honestly and be sure to ask their children for their opinions and

ideas. Issues may come up more than once and parents should remain patient when you answer the

questions again. For young children, parents, after talking about the earthquake, might read a favorite

story or have a relaxing family activity to help them calm down. Parents should also tell children they are

safe and spend extra time with them. They could play games outside or read together indoors. Most

importantly, be sure to tell them you love them.

1. What's the passage mainly about?

A. How to prepare before an earthquake strikes.

B. What to do in an earthquake.

C. How to face the loss of a loved one in an earthquake.

D. How to help children recover mentally from an earthquake.

2. The underlined phrase "contend with" in Paragraph 1 can be replaced by "______".

A. deal with

B. make up

C. put off

D. turn back

3. When children ask the same question again, parents should ______.

A. read a favorite story to comfort them.

B. ask them to help do some housework.

C. be patient and answer the question again.

D. take them out to play games.

4. Which of the following pieces of advice is NOT mentioned in the passage?

A. Keep a close watch on children's behavior.

B. Tell the children they are safe.

C. Tell the children you love them.

D. Ask educational experts for help.