1. Why is water cycle important?
A. It causes droughts B. It is not useful to us C. It is a source of money D. It provides people, animals, and plants with water
2. What would happen if the water cycle stopped?
A. Stopping it would clean our rivers B. Stopping it would cause endless drought C. Stopping it would make the plants grow D. None of the above
3. Which of the following human activities affect the water cycle? A. Swimming and fishing B. cleaning up streams and rivers C. Damming rivers for hydroelectricity D. Planting trees along the river banks
4. Which of the following statements is false? A. Water can change into three phases. B. Water gives the earth its characteristic blue color as seen from outer space. D. Water cycle is important because it is how water reaches plants, animals and humans.

1.The water cycle is an extremely important process because it enables the availability of water for all living organisms and regulates weather patterns on our planet. If water didn't naturally recycle itself, we would run out of clean water, which is essential to life.

2.With no water supply, all vegetation would soon die out and the world would resemble a brownish dot, rather than a green and blue one. Clouds would cease to formulate and precipitation would stop as a necessary consequence, meaning that the weather would be dictated almost entirely by wind patterns

3.A number of human activities can impact on the water cycle: damming rivers for hydroelectricity, using water for farming, deforestation and the burning of fossil fuels.

4.Water blocks the radiation of white light (sunlight). In reality, the sunlight looks white from a mixture of lights of many different colors. As illumination enters the water, the water consumes white light and reflects just blue light, lights of all colors. The earth from space, thus, looks blue.