问题 实验题

如图所示,在竖直板上不同高度处各固定两个完全相同的圆弧轨道,轨道的末端水平。在它们相同位置上各安装一个电磁铁,两个电磁铁由同一个开关控制,通电后,两电磁铁分别吸住相同小铁球A、B,断开开关,两个小球同时开始运动。离开圆弧轨道后,A球做平抛运动,B球进入一个光滑的水平轨道,则:B球进入水平轨道后将做_____________运动;改变A轨道距离B轨道的高度,多次重复上述实验过程,总能观察到A球正好砸在B球上,由此现象可以得出的结论是_____________;若某次两小球相碰的位置恰在水平轨道上的P点处,固定在竖直板上的方格纸的正方形小格每边长为5cm,则可算出A铁球刚到达P点的速度为_____________m/s。

答案

匀速直线,A球在水平方向作匀速直线运动,

阅读理解

阅读理解。

     Spending just a few hours a week online may make people feel more socially isolated(孤立的),

lonely and downhearted(沮丧的), according to a two-year study of nearly 100 families with the

Internet.

     "We were surprised to find that social technology has such bad effects on social communications,"

the lead author, Dr. Robert Kraut of Carnegie Mellon University in Pittsburgh, Pennsylvania, said in a

statement to the news. The findings suggest that "Rather than encourage students to use the Internet

alone for research, teachers might give pupils online group homework to complete with classmates.

Local groups might build websites that allow neighbors to discuss local affairs(地方事务)."

     "Before the technology develops and can be really more beneficial, people should control(控制)

their wishes to use much of the Internet," Dr. Kraut and other experts advise. In order to control their

children and encourage family activities, parents might think of putting the computer in the living room

rather than in a child's room, they suggest.

     Dr. Kraut also suggests that when surfing on the net, especially when chatting with strangers on the

net, children should not use their real names, and that they should not tell the addresses, telephone

numbers to the strangers.

1. According to the research, surfing on the Internet can make people feel more            .

A. excited              

B. communicative

C. lonely                

D. happy

2. This study was made by            .

A. 100 families

B. Dr. Kraut and other experts

C. the newspaper

D. Dr. Kraut only

3. This research work took          .

A. a week          

B. a few hours

C. two years        

D. more than 100 days

4. According to the context(上下文), "beneficial" means "            " in Chinese.

A. 有害的        

B. 发展的

C. 有趣的        

D. 有益的

5. Which of the following do the experts suggest?

A. Teachers should ask the students to finish their homework alone on the Internet.

B. Schools should build websites for students to discuss problems on the Internet.

C. Instead of putting the computer in the sitting room, parents should put it in a child's room.

D. Children should not give their real names, addresses or telephone numbers to the strangers.

填空题