夏、商、西周灭亡的共同因素是 [ ] A.诸候的反叛 B.统治者残暴,失去民心

题型:选择题

问题:

夏、商、西周灭亡的共同因素是 [ ]

A.诸候的反叛

B.统治者残暴,失去民心

C.国人暴动

D.少数民族内侵

考点:商汤灭夏和武王伐纣(盘庚迁殷、牧野之战,国人暴动)西周的结束
题型:选择题

以颈部和额、颏、颅等骨作为支抗的力属于()

A.重度力

B.间歇力

C.矫形力

D.颌外力

E.肌力

题型:选择题

蛇咬伤后缚扎急救时,下列哪一项是错误的:

A.伤口排毒或服药后4小时可解除缚扎

B.伤口近心端缚扎

C.缚扎时间可持续8~10小时

D.每隔15~30分钟放松一次

E.咬伤超过12小时不宜缚扎

题型:选择题

Philo Farnsworth was a man who made it possible for one of the most important communication devices — television to be created. Philo was born on August 19th, 1906, near Indian Creek in the western state of Utah. He attended a very small school near his family’s farm. He did very well in school. He asked his teacher for special help in science. The teacher began helping Philo learn a great deal more than most young students could understand.

One night, Philo read a magazine story about the idea of sending pictures and sound through the air. Anyone with a device that could receive this electronic information could watch the pictures and hear the sound. The magazine story said some of the world’s best scientists were using special machines to try to make a kind of device to send pictures.

14-year-old Philo decided these famous scientists were wrong and that mechanical devices would never work. He decided that such a device would have to be electronic. Philo knew electrons could be made to move extremely fast. All he would have to do was to find a way to make electrons do the work.

Very quickly Philo had an idea for such a receiver. It would trap light in a container and send the light on a line of electrons. Philo called it “light in a bottle”.

Several days later, Philo told his teacher about a device that could capture pictures. He drew a plan for it, which he gave his teacher. Philo’s drawing seemed very simple, but it clearly showed the information needed to build a television. In fact, all television equipment today still uses Philo’s early idea.

Philo Farnsworth was only 14 years old then. He knew no one would listen to a child. In fact, experts say that probably only ten scientists in the world at that time could have understood his idea.

On September 7th, 1927, Philo turned on a device that was the first working television receiver. In another room was the first television camera. Philo had invented the special camera tube earlier that year.

The image produced on the receiver was not very clear, but the device worked. In1930, the United States government gave Philo patent documents. These would protect his invention from being copied by others.

56. Before he was 14 years old, _______________.

A. Philo had formed the idea of sending pictures and sound through the air

B. Philo had learned a great deal in science from his father

C. Philo had helped his parents on their family’s farm

D. Philo had had a very strong interest in science

57. How did Philo get the idea of inventing a television?

A. By learning from his science teacher.

B. By reading a story about the idea in a magazine.

C. By thinking hard himself.

D. By using his knowledge about electrons.

58. Philo referred to “ _________ ” when he called something “light in a bottle”.

A. a container sending pictures and sound through the air

B. a light box with a line of electrons in a bottle

C. a receiver that held light and sent it on a line of electrons

D. a way to make electrons send pictures

59. We can infer from the passage that _________________.

A. without his teacher’s help, he would never have become interested in science

B. he made the first working television receiver and the first television camera himself

C. Philo’s early ideas about the television could not be understood by most people of that time

D. his invention was recognized and protected immediately he made it

60. In the passage, the author mainly tells us _______________.

A. that Philo Farnsworth was a great inventor

B. when and where the television was invented

C. who made it possible to create television

D. how Philo Farnsworth invented the television

题型:选择题

海船和内河船舶的乘客定额证书为5年有效期。

题型:选择题

(四)题6-7,分析螺纹连接中的画法错误,并在指定位置绘制正确的视图。题6-8、题6-9补全螺栓连接两视图中所缺的图线(主视图为全剖视图,俯视图为外形)。

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