如图所示,用声呐测量海洋某处的深度,已知超声波在海水中的速度是1500m/s,如

题型:选择题

问题:

如图所示,用声呐测量海洋某处的深度,已知超声波在海水中的速度是1500m/s,如果发出信号6s后收到反射回来的声波,那么海洋被测处的深度约为(  )

A.1500m

B.4500m

C.9000m

D.18000m

考点:回声及回声测距离的应用
题型:选择题

有一辆汽车以60000元购入,实行加速折旧,每年的运行维持费用和折旧后每年残余价值如表所示。试计算其最佳更新期。

题型:选择题

下面不属于周朝制度的是

[ ]

A.禅让制

B.奴隶制

C.世袭制

D.分封制

题型:选择题

It’s common to hear the honking of horns in New York. Whoever tries every day to get more than a few minutes of sleep in the city will tell you that he could do nothing about it! Honking of horns is just one of their most widely enjoyed pastimes.

But Aaron, a Japanese website developer has had enough of it. Once, the 31-year-old man approached the open window to wait for the driver to finish honking, delivered a polite "excuse me" and then yelled " Ho-o-o-o-onk!", which suggests fierce anger in Japan. Then he threw three eggs from the window of his apartment on to a passing car honking loudly below when his patience was worn out. Instead of apologizing to him, the driver threatened to kill him angrily. So, nobly, Aaron turned to non-violence. He started writing anti-honking haiku verses, a form of Japanese poetry, and submitted them to local newspapers:

Oh .forget Enron;

The problem around here is;

All the damn honking

(Enron: a major American company that recently caused a scandal by going bankrupt be­cause of corrupt(腐败) mismanagement)

"Then this kind of chain reaction started happening," Aaron says. "All these other haiku star­ted appearing that I haven't written." Aaron’ s community is now covered in anti - hon­king poetry, written by all walks of life, ranging from scary environmental activist types to violent revolutionaries:

Patience slowly fades;

Residents store up their eggs;

That day is coming soon.

It’s no surprise that Aaron has started a website — www. honku. org — and now people from across the country send him news of their own anti - honking activities. It seems that poetry can change the world after all. Then, just recently, anti-anti- honking haiku started to appear, taped up by locals who thought Aaron should stop worrying about honking and start wor­rying about starving children, say, or war in the  Middle East instead. Aaron has an answer for that. "Stop me if this is too tenuous(不靠谱的) ," he says," but they talk about the violence in the Middle East like it' s a force of nature, like it' s beyond our control. But actually it's kind of like the honking - the violence is man -made. If we can figure out how to stop honking on the streets, I think we could learn some things that we could use on a large scale. "

小题1:The first paragraph of the passage is intended to tell us that_______.

A.New Yorkers have formed a habit of honking while driving

B.most New Yorkers enjoy sleeping late in the morning

C.honking noise has influenced people's life in New York

D.New Yorkers enjoy listening to the honking of horns小题2:What is Aaron’s final response to the frequent honking of horns?

A.Pretended to ignore it.

B.Screamed at the driver.

C.Acted in a peaceful way.

D.Complained to the government.小题3:According to the passage, most New Yorkers think Aaron's response is ___.

A.pointless

B.abnormal

C.sensitive

D.acceptable小题4:Faced with the criticism of his anti-honking campaign, Aaron notes that___.

A.fierce violence in the Middle East is more of an issue worthy of concern

B.finding the solution to anti - honking is as meaningful as that to starvation

C.big issues are beyond our control while small ones are under our control

D.if not handled properly, honking may cause serious problems like starvation

题型:选择题

质量相等的两木块A、B用一轻弹簧栓接,静置于水平地面上。现用一竖直向上的力F拉动木块A,使木块A向上做匀加速直线运动。从木块A开始做匀加速直线运动到木块B将要离开地面时的这一过程,下列说法正确的是(设此过程弹簧始终处于弹性限度内)()

A.力F一直增大

B.弹簧的弹性势能一直减小

C.木块A的动能和重力势能之和一直增大

D.两木块A、B和轻弹簧组成的系统机械能先增大后减小

题型:选择题

Class类是一个特殊类,它在编译时由 【7】 自动生成,并伴随每一个类。

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