如果柱面透镜的轴向在135度上,则该透镜的最大屈光力是在()上。A、45度 B、90度

题型:单项选择题

问题:

如果柱面透镜的轴向在135度上,则该透镜的最大屈光力是在()上。

A、45度

B、90度

C、135度

D、180度

考点:眼镜验光员中级眼镜验光员中级眼镜验光员题库
题型:单项选择题

在光滑的水平面上有一直角坐标.质量为m=4 kg的物体,沿y轴正方向以大小为5 m/s的初速度通过坐标原点O,此时给物体施加一沿x轴正方向的恒力F。一段时间后物体恰好通过点P,P点的坐标为(2.5 m,5 m)。求:

(1)物体由O运动到P点的时间;

(2)恒力F的大小;

(3)物体在P点的速度的大小和方向

题型:单项选择题

依据我国现行规定,对于个别情况特殊的国家重点建设项目,经( )批准,可适当降低资本金比例。

A.省级政府

B.国务院

C.国家发展和改革委员会

D.政府主管部门

题型:单项选择题

阅读理解。

     Jeffrey Bezos, the founder, president and chairman of the board of Amazon.com, was born in Albuquerque,

New Mexico. His mother's ancestors were early settlers in Texas, and over the generations had acquired a

25,000 acre farm at Coutlla. Jeffrey spent most summers of his youth working with his grandfather on their

farm.

     Jeffrey showed intense and varied scientific interests at an early age. He set up an electric alarm to keep his

younger sisters and brothers out of his room and changed his parents' garage into a laboratory for his science

projects.

     After he graduated from Princeton University with a degree in computer science and electrical engineering,

Jeffrey Bezos found employment on Wall Street, where computer science was increasingly in demand to study

market trends. He rose quickly, becoming a senior vice president, and looked forward to a bright career in

finance, when he made a discovery that changed his life, and the course of business history.

     In 1994, there was still no Internet commerce to speak of. One day that spring, Jeffrey Bezos observed that

Internet usage was increasing by 2,300 percent a year. He saw an opportunity for a new circle of commerce,

and immediately began considering the possibilities.

     Bezos founded Amazon.com in 1994, setting up the original company in his garage. The company was

called Amazon for the seemingly endless South American river with its numberless branches. It started as an

online bookstore but soon diversified (多样化) to all kinds of products. His work with Amazon eventually led

him to become one of the most excellent dot-com entrepreneurs (企业家). He was named Time magazine's

Person of the Year in 1999. In 2008, he was selected by U.S. News & World Report as one of America's Best

Leaders. Bezos' Amazon has become "the Earth's biggest anything store". Amazon.com is now called" one of

the smartest strategies in business history".

     Today, Jeffrey Bezos lives north of Seattle and is increasingly concerned with charity (慈善) activities.

"Giving away money takes as much attention as building a successful company," he has said.

1. In his childhood, Bezos ____.

A. had to work with parents on their farm all day long

B. showed great interest in science

C. didn't get along well with his brothers and sisters

D. wanted to become a businessman

2. Bezos named his company Amazon with the aim of ____.

A. opening numberless branches all over the world

B. living a quiet life along the Amazon River

C. earning endless money and being wealthy

D. wishing his company to run smoothly and endlessly

3. Which of the following isn't mentioned in the passage?

A. How hard Bezos studied physics in Princeton University.

B. "Amazon.com" only sold books in the beginning.

C. Bezos not only devoted his life to Internet commerce but also to charity.

D. The reason why Jeffrey Bezos decided to found Amazon.com.

4. It can be inferred from the passage that ____.

A. it was Bezos's grandfather on the farm who helped him a lot

B. Bezos invented e-commerce to win the world fame overnight

C. Bezos is aiming at being "the Earth's biggest bookstore"

D. Bezos has a sharp business mind and a kind heart

题型:单项选择题

已知某处最大工作压力为0.9MPa,最小工作压力为0.4MPa,压力表适合的量程为( )MPa。

A.0~1.0
B.0~1.2
C.0~1.3
D.0~1.6

题型:单项选择题

A/O系统称为()系统,由()、()和()组成,具有普通活性污泥法的特点,同时又具有较高的脱氮功能。

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