下列四种现象中,是由于光的直线传播形成的是[ ] A. 平面镜中的像 B.

题型:选择题

问题:

下列四种现象中,是由于光的直线传播形成的是[ ]

A.

       平面镜中的像

B.

       草坪上父子的影

C.

      水中铅笔变弯

D.

     放大镜中红绿蓝光点

考点:光的直线传播现象
题型:选择题

当某种卫生服务的价格上升1%,其需求数量增加0.2%,说明该服务为

A.完全弹性

B.富有弹性

C.单元弹性

D.缺乏弹性

E.完全无弹性

题型:选择题

根据短文内容填空,每空不超过4个单词。

Mr. Clarke joined the army when he was eighteen. Four years later he came back to his hometown and found work in a post office. He worked hard but he liked drinking and it brought him a lot of trouble. One day he drank too much and lost a mailbag and he was soon sent away. He couldn’t find any work in the town and he had to beg(乞讨) in the street. Now his clothes are dirty and broken and sometimes he’s hungry. 

One morning he was begging at the station. He saw a woman in beautiful clothes come out by the exit. He went close to her and hoped that she gave him some money. The woman had a look at him and hurried to cover her nose with her hand.

“It seems that you have come from the hell(地狱).” The woman called out.

Mr. Clarke understood she was such a woman who never helped the poor and said, “You’re right, madam. I’m really from the hell.”

“Why not stay there, then?”

“There is no room for the poor people like me.” said Mr. Clarke.  “Only the rich men live there!”

小题1:When he was 22, Mr. Clarke found a job in a _______________.

小题2:Mr. Clarke was sent away because he lost                .

小题3:Sometimes Mr. Clarke is hungry because he has nothing              .

小题4:The woman hurried to             her nose because she thought Mr. Clarke was dirty.

小题5:Mr. Clarke’s words meant that the hell was only for the             like the woman.

题型:选择题

二尖瓣口重度狭窄时,超声心动图检测血流频谱平均跨瓣压差数值应为()

A.10mmHg

B.25mmHg

C.5mmHg

D.8mmHg

E.16mmHg

题型:选择题

阅读短文,根据上下文填写所缺单词。(每空2分)

Do you often communicate with your parents? Some parents are always comparing their 小题1:with themselves or other people when they were young.

"When I was your age," a father said to his sixteen - year - old son one day, "I was at the top of my class every year. And I小题2:what I wanted to do when I left school. I had goals (目标).

You are always at the bottom (最后) of your class小题3:you have no goals. " The man' s son said nothing. He had already heard this from his father many times. "And when your mother was your age," the young man' s father went小题4:, "she had a good job and she小题5:lots of money. You don' t even have a part - time job . You earn nothing. "The man' s son still said nothing. He had heard this before, too. "And when your小题6:brother was your age," the young man' s father said, "he studied hard. But you just waste your time. "And the man' s son still said nothing.

Finally, the young man's father said, "And when Abraham Lincoln was your age, he worked all day and studied at night. "This time the son小题7:stay silent.

"And when Abraham Lincoln was your age, father," he said, "He was the President of小题8:United States.小题9:are you?" His father had no answer小题10:this.

Are your parents always comparing you with others? And what's your reply? Do you have a better way to communicate with each other?

题型:选择题

不属于铸铁管胶圈的挑选标准是()。

A、材质紧密

B、无裂缝

C、接头应平整牢固

D、外观应粗细均匀

更多题库