Read the fact sheet. What happens to water when it falls to the Earth?

                                                      THE WATER CYCLE

Now here is a challenge for you. Go and get a glass of water and take a look at it. Can you guess how old it is? Well, your water perhaps fell from a cloud just a couple of weeks ago, but it has been around for the same length of time as planet Earth! That means that your glass of water was around when the first creatures swam in the sea and when the dinosaurs roamed the Earth. But how is this possible?

The fact is that the quantity of water on the Earth remains the same over time and it constantly goes through the water cycle. In the cycle, there is continuous movement of water on, above and below the surface of the Earth. Firstly, the sun heats the water in the rivers, seas and oceans, and it evaporates into the air. Plants and trees lose water, too, and this also goes up into the air. The water vapour then cools and condenses into small drops which form clouds. You can see how condensation happens if you look again at your glass of water on a hot day. After a short time, water from the air condenses onto the cold glass. Back to the sky, though, and the next step is that the clouds gradually get heavier and heavier until they can’t hold the water any more, and it falls to Earth as rain, sleet or snow.

Water can change state from liquid to vapour to solid during the cycle, but any form of water that falls from the clouds is called precipitation. When on Earth, some of the water runs into rivers, lakes and streams and becomes surface water. Some enters the ground and forms underground rivers or lakes before eventually flowing back to the seas and oceans. The cycle is complete.

Read the text again and answer the following questions.

1. What are humans still wondering nowadays?

2. Why does a habitable planet need to have the correct amount of air?

3. What happens if a planet is too small?

4. How long does a day on Mars last?

5. Why can we not live on Mars?

THE TEXT:

Nowadays humans are still wondering what planets in outer space might support life.

Scientists say planets need to meet three main conditions to support life. Firstly, they must have liquid water, so their temperature must not be too high or too low. Secondly, the planets need to have the correct amount of air so that they can hold an atmosphere around. Finally, their size is also important. If a planet is too small, its gravity is not strong enough to hold an enough amount of air. If it is too big, its gravity will be so strong that it will hold too much air.

Scientists are using space telescopes to find habitable planets. According to them, Mars is one of the most promising planets for life in our solar system. It is a planet like Earth. Its days last for 24.5 hours and its seasons are similar to Earth's. Although scientists have not found actual water on Mars, there seems to be traces of it on the planet's surface. However, the climate on Mars is unsuitable for human life because it is too cold and Mars lacks oxygen to support human life.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions

Three mile island nuclear power plant

America’s worst accident at a civilian nuclear power plant occurred on March 28, 1979, at Three Mile Island. Operators were trying to repair a problem with piping in the water circulation system, and they accidentally blocked the flow of water. This stopped the removal of heat from the reactor, and began a series of events that would change the way America thought about nuclear power.

Within ten seconds after the flow of water was blocked, the reactor vessel became hotter and the pressure rose. Safety control rods were automatically thrust down into the reactor, causing the chain reaction to stop completely. Pressure, however, continued to build. A relief valve opened but failed to close. As a result, too much water escaped, and the reactor began to melt down.

[1] Large quantities of radioactivity began to leak from the reactor. [2] Most of the radioactivity was contained, and it is likely that no one received a harmful amount of radiation. [3] “Three Mile Island” became the reason that many Americans are afraid of nuclear power to this day. [4]

What is the most likely reason why many Americans are still afraid of nuclear island?

A. They have heard about many accidents like the one at Three Mile Island.

B. They were at Three Mile Island

C. They believe that a situation like Three Mile Island could happen again

D. Nuclear power plants are always dangerous.

Read the following passage, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth’s gravity pulls it. But every cloud is made of water droplets or ice crystals. Why doesn’t rain or snow fall constantly from all clouds? The droplets or ice crystals in clouds are exceedingly small. The effect of gravity on them is minute. Air currents move and lift droplets so that the net downward displacement is zero, even though the droplets are in constant motion.

Droplets and ice crystals behave somewhat like dust in the air made visible in a shaft of sunlight. To the casual observer, dust seems to act in a totally random fashion moving about chaotically without fixed direction. But in fact dust particles are much larger than water droplets and they finally fall. The cloud droplet of average size is only 1/2500 inch in diameter. It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it does not fall out of moving air at all. Only when the droplet grows to a diameter of 1/125 inch or larger can it fall from the cloud. The average raindrop contains a million times as much water as a tiny cloud droplet. The growth of a cloud droplet to a size large enough to fall out is the cause of rain and other forms of precipitation. This important growth process is called “coalescence”.

What are water droplets?

A. They are ice crystals. 

B. They are small drops of dew.

C. They are watery fruits. 

D. They are animals living on ice.

Read the following passage, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth’s gravity pulls it. But every cloud is made of water droplets or ice crystals. Why doesn’t rain or snow fall constantly from all clouds? The droplets or ice crystals in clouds are exceedingly small. The effect of gravity on them is minute. Air currents move and lift droplets so that the net downward displacement is zero, even though the droplets are in constant motion.

Droplets and ice crystals behave somewhat like dust in the air made visible in a shaft of sunlight. To the casual observer, dust seems to act in a totally random fashion moving about chaotically without fixed direction. But in fact dust particles are much larger than water droplets and they finally fall. The cloud droplet of average size is only 1/2500 inch in diameter. It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it does not fall out of moving air at all. Only when the droplet grows to a diameter of 1/125 inch or larger can it fall from the cloud. The average raindrop contains a million times as much water as a tiny cloud droplet. The growth of a cloud droplet to a size large enough to fall out is the cause of rain and other forms of precipitation. This important growth process is called “coalescence”.

What can be inferred about drops of water larger than 1/125 inch in diameter?

A. They never occur.

B. They are not affected by the force of gravity.

C. In still air they would fall to the ground.

D. In moving air they fall at a speed of thirty-two miles per hour.

Read the following passage, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth’s gravity pulls it. But every cloud is made of water droplets or ice crystals. Why doesn’t rain or snow fall constantly from all clouds? The droplets or ice crystals in clouds are exceedingly small. The effect of gravity on them is minute. Air currents move and lift droplets so that the net downward displacement is zero, even though the droplets are in constant motion.

Droplets and ice crystals behave somewhat like dust in the air made visible in a shaft of sunlight. To the casual observer, dust seems to act in a totally random fashion moving about chaotically without fixed direction. But in fact dust particles are much larger than water droplets and they finally fall. The cloud droplet of average size is only 1/2500 inch in diameter. It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it does not fall out of moving air at all. Only when the droplet grows to a diameter of 1/125 inch or larger can it fall from the cloud. The average raindrop contains a million times as much water as a tiny cloud droplet. The growth of a cloud droplet to a size large enough to fall out is the cause of rain and other forms of precipitation. This important growth process is called “coalescence”.

What does “in constant motion” in paragraph 1 mean?

A. moving all the time 

B. always having feeling

C. never changing 

D. falling down easily

Read the text and answer the following questions.

The Earth was formed about 4.7 billion years ago. The Earth's shape is very close to that of a sphere, not perfectly spherical. The Earth's equatorial diameter is about 12,756 km, which is slightly larger than the polar diameter; about 12,714 km Surface Area of the Earth is 510,065,600 km2 of which 148,939,100 km2 (29.2%) is land and 361,126,400 km2 (70.8 %) is water. The Earth rotates on its axis, an imaginary straight line through its centre. The two points where the axis of rotation intersects the Earth's surface are called as the poles, one of them is called the North Pole and the other is known as the South Pole. One rotation with respect to Sun is completed in 24 hours, called a solar day.

1. When was the Earth created?

2. How is the Earth?

3. What main elements does the Earth include?

4. What are the places of the axis of rotation intersects the Earth‟s surface called?

5. How long is a solar day completed?

Read the following passage, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth’s gravity pulls it. But every cloud is made of water droplets or ice crystals. Why doesn’t rain or snow fall constantly from all clouds? The droplets or ice crystals in clouds are exceedingly small. The effect of gravity on them is minute. Air currents move and lift droplets so that the net downward displacement is zero, even though the droplets are in constant motion.

Droplets and ice crystals behave somewhat like dust in the air made visible in a shaft of sunlight. To the casual observer, dust seems to act in a totally random fashion moving about chaotically without fixed direction. But in fact dust particles are much larger than water droplets and they finally fall. The cloud droplet of average size is only 1/2500 inch in diameter. It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it does not fall out of moving air at all. Only when the droplet grows to a diameter of 1/125 inch or larger can it fall from the cloud. The average raindrop contains a million times as much water as a tiny cloud droplet. The growth of a cloud droplet to a size large enough to fall out is the cause of rain and other forms of precipitation. This important growth process is called “coalescence”.

What is the diameter of the average cloud droplet?

A. 1/16 inch 

B. 1/125 inch

C. 1/2500 inch 

D. one millionth of an inch