Предмет: Математика, автор: dvoechnik25

Плииииииззззззз очччеееееенььь срочнооо

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Автор ответа: Анелямм

надеюсь что помогла.

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devgor: там 19 с минусом в условии

Анелямм: ок через 5 мин будет ответ

Автор ответа: devgor

вот решение, только зачеркнутую линию не рисуй)

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Предмет: Английский язык, автор: Aurea6458

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Read this passage and answer the questions that follow.

Today we have many ways to tell time. Watches, clocks, cell phones, and computers all tell the time. This passage is about the history of different ways of telling time and its importance.

What Time Is It?

Believe it or not, there was a time when humans were not concerned with the exact time of day. There were no clocks or watches. Instead, their daily activities were guided by the rising and the setting of the sun. As societies became more organized, the idea of "time" grew in importance.

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There were several devices created to supplement or replace sundials. One such device was the notched candle, which let people calculate the time by looking at how far down the candle had burned. The Chinese came up with a somewhat similar contrivance by burning a knotted rope.

Some ancient people used a water clock known as a "clepsydra." The clepsydra

determined time by measuring the flow of water dripping from a bowl or vessel. As the water level rose or fell in the bowl, markings on the inside of the bowl would indicate the time. Another perhaps more familiar timepiece was the hourglass. The hourglass operated by having sand trickle through the small opening separating the top section of the glass from the bottom section. When the bottom section was full, an hour had passed.

These early efforts to tell time served a need, but none of them offered a precise measure of time. With the introduction of the first weight-driven clock in 1286, the technology to develop more accurate means of keeping time had begun. By the mid-1300s, an astronomer and physician named Giovanni de’ Dondi completed an early astronomical clock. He produced a seven-sided clock whose dials showed the sun, the moon, and the known planets. In addition to the 24 hours, it showed the times of sunrise and sunset, religious holidays, and the cycles of the moon. His "astrarium" was a remarkable advance over previous timepieces. However, it wasn’t until 300 years later, in 1650, that the first clock using two hands to tell the time was made.

Through the next centuries, numerous changes took place in the clock industry. Some clockmakers produced clocks that were works of art with beautiful gilt figures surrounding the clock faces. Others refined the size all the way down from the dimensions of huge clocks in bell towers to those of today’s wristwatches. Power sources to control the clock mechanisms changed, too – from coil springs to quartz.

The greatest breakthrough in timekeeping occurred in 1999. The United States National Institute of Standards and Technology (NIST) introduced the atomic clock. This clock has paved the way for global positioning systems (GPS) to help in the navigation systems used in today’s automobiles. Just how accurate is this new clock? It is the most accurate clock in the world. In 20 million years, it will neither gain nor lose one second as it tells time.

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1. Thousands of years ago, people would base their activities upon the

A. sound of the rooster.

B. amount of work to be done.

C. phases of the moon.

D. rising and setting of the sun.

2. The author attempts to

A. convince readers to buy a new kind of clock.

B. tell the story of how the atomic clock was built.

C. challenge readers to find a better way to tell time.

D. describe different ways people have told time.

3. What was the oldest form of timekeeping?

A. clepsydra

B. atomic clock

C. astrarium

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A. It allowed clock makers to create beautiful clocks.

B. It allowed timepieces to become hand-held.

C. It marked the beginning of new technology.

D. It marked the end of using the sun to tell time.

5. The atomic clock is

A. not built yet.

B. dangerous.

C. outdated.

D. precise.

6. What was the biggest advance in timekeeping?

A. the sundial

B. the atomic clock

C. global positioning systems

D. the wristwatch

[7 points]

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