明明取一粒菜豆种子,并提供了合适的条件让它萌发,然后根据植物发芽3天的根尖示意图

题型:选择题

问题:

明明取一粒菜豆种子,并提供了合适的条件让它萌发,然后根据植物发芽3天的根尖示意图,选出7天以后植物根尖的正确图形

[ ]

A.

B.

C.

D.

考点:根的生长
题型:选择题

下列能量转化过程,通过化学变化实现的是[ ]

A.地热发电

B.核反应发电

C.火力发电

D.风能发电

题型:选择题

施工管理中的经济责任制的基本原则是()。

A、责、权、利相结合;

B、国家、集体、个人利益相统一;

C、利益最大化;

D、职工劳动所得和劳动成果相联系。

题型:选择题

阅读理解

     Three-Dimensional (3D) movies have been becoming more and more popular in recent years. It

seems 3D TV sets may be going into family households in the near future. While new digital 3D

technology has made the experience more comfortable for many, for some with eye problems, long 3D

viewing may result in an aching head, doctors say.

     "There are a lot of people walking around with very minor eye problems, which under normal

situations, the brain deals with naturally," said Dr Michael Rosenberg, an ophthalmologist (眼科医师)

in Chicago. He said in a 3D movie, these people face a completely new sensory experience. "That

translates into greater mental effort, making it easier to get a headache," Rosenberg told Reuters.

     In normal vision, each eye sees things at a slightly different angle. "When that gets processed in the

brain, that creates the perception (感觉) of depth," said Dr Deborah Friedman, an ophthalmologist in

New York. The images people see in three dimensions in the movies are not calibrated (校准的) in the

same way that their eyes and brain are. "If your eyes are a little off to begin with, then it's really throwing

a whole degree of effort that your brain now needs

to exert (竭尽全力)," he said.                      

     Dr John Hagan, a Kansas City ophthalmologist, said some people who do not have normal depth

perception cannot see in 3D at all. He said people with eye muscle problems, in which the eyes are not

pointed at the same object, have trouble processing 3D images.

Rock Heineman, a spokesman for RealD, a provider of 3D equipment to theaters, said headaches and

nausea were the main reasons 3D technology never took off.

     Heineman said older 3D technology used two film projectors(放映机), one that projected a left-eye

image and one that projected a right-eye image. Three-D glasses would allow viewers to see a different

image in each eye.

     "People often complained of headaches and it was really because the projectors weren't lined up,"

Heineman said.

     Now his company has developed a new single digital projector, which switches between the left and

the right-eye image 144 times a second, to help overcome some of the old problems.

     "By going to a single digital projector, those problems were solved," he said. Friedman said he thinks

most people will do fine with 3D movies and with 3D TVs, but Rosenberg said people may quickly tire

of the novelty (新鲜事物). "I suspect there will be a lot of people who say it's sort of neat, but it's not

really comfortable," he said.

1. The text is mainly about ____.

A. the reasons why people like 3D movies

B. how to improve 3D technology

C. the development of 3D technology in recent years

D. causes of headaches and nausea when people watch 3D movies

2. The underlined phrase "took off" could be replaced by "______".

A. became popular              

B. flew in the sky

C. left hurriedly              

D. removed one's clothes

3. This article implies that _____.

A. people do not like new things like 3D movies

B. 3D TVs will completely take the place of old TV sets

C. 3D technology is the most important technology ever

D. those with eye muscle problems should not watch 3D movies

4. We can learn from what Rosenberg said in the last paragraph that

A. a single digital projector could solve all the problems with 3D technology

B. people will gradually become comfortable with 3D movies and TVs

C. the appeal of 3D movies and "TVs may fade

D. most people will actually enjoy the 3D experience

题型:选择题

计算机硬件系统是由()、主板、存储器、输入和输出设备等部件构成。

A.硬盘

B.软盘

C.键盘

D.中央处理器

题型:选择题

气候分区为1-4-1的地区,第一个数字1代表( )。

A.高温气候区
B.低温气候区
C.雨量气候区
D.温度气候区

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