Cambridge University Press Edited by Jack C. Richard and David Nunan

Cambridge University Press Edited by Jack C. Richard and David Nunan

Merely thinking and talking about what has happened will often mark it possible for the teacher to modify their own behavior.

T- Try again.

T- Team-teach.

Some options may require demonstration. It is difficult, for explain in words the characteristics of effective drilling, or the efficient organization of group work-such things are easier to demonstrate.

T- Train.

For some purpose or in some contexts, training may be the most effective or economical or feasible strategy. This will generally take place outside the classroom.

Unit 6: Science and Unit 6: Science and TechnologyTechnology

Topic : ImpactsTopic : Impacts

Matthayomsuksa 4Matthayomsuksa 4

The Water Cycleand

Human Impact on water Cycle

Vocabulary

water cyclewater cycle

evaporate evaporate

precipitation precipitation

aquifer aquifer

pesticides pesticides

hazardous hazardous

Introduction Earth's water is always moving and the Water Cycle (also known as the Hydrologic Cycle) describes this movement of water on, above, and below the surface of Earth. Since the water cycle is truly a "cycle," there is no beginning or end. Water changes states among liquid, vapor, and ice at different places in the cycle, and these changes are happening all over the world at the same time.

The Water Cycle

The sun evaporates water from lakes and oceans. As the air rises, it cools. The water vapor condenses into tiny droplets of water. The droplets crowd together and form a cloud. Wind blows the cloud towards the land. The tiny droplets join together and fall as precipitation to the ground. The water soaks into the ground and collects in rivers and lakes. The cycle that never ends has started again!

Human Impact on water CycleHuman Impact on water Cycle

Human Impact on water Cycle

The earth's water supply is constant, but man is able to changing the series of this fundamental supply. Population increases, rising living standards and industrial and economic growth have placed greater stress on the natural environment. Man activities can cause inequity in the hydrologic equation and can affect the quantity and quality of natural water resources available to current and future generations.

Water used by households, industries, and farms have increased. People demand clean water at reasonable costs, yet the amount of fresh water is limited and the easily accessible sources have been developed. As the population increases, so will our need to withdraw more water from rivers, lakes and aquifers, threatening local resources and future water supplies. Domestic, agricultural, and industrial wastes, including the intensive use of pesticides, herbicides and fertilizers, after overload water supplies with hazardous chemicals and bacteria.

Together, these various effects determine the amount of water in the system and can result in extremely negative consequences for river watersheds, lake levels, aquifers, and the environment as a whole. Therefore, it is vital to learn about and protect our water resources.

Structure(If Clause)

Conditional Sentence Type 1

→ It is possible and also very likely that the condition will be fulfilled.

Form:

ifif + Simple PresentSimple Present will-Futurewill-Future,,

For examples:

• If there is not enough water, plants will dry up.

• If there is not enough water, animals will be thirsty.

• If it rains, there will be more water on the ground.

Activity1: T-Try againMerely thinking and talking about what has happened will often mark it possible for the teacher to modify their own behavior.

If there is not enough water, plants will dry up. If there is not enough water, animals will be thirsty.

Example

The The QuestionQuestion

http://shoalwater.nsw.gov.au/Education/watercycle_experiment.htm