Water is always on the move. Rain falling today may have been water in a distant ocean days before. And the water you see in a river or stream may have been snow on a high mountaintop. Water is in the atmosphere, on the land, in the ocean, and underground. It moves from place to place through the water cycle.
Where's the water?
There are about 1.4 billion km3 of water (336 million mi3 of water) on Earth. That includes liquid water in the ocean, lakes, and rivers. It includes frozen water in snow, ice, and glaciers, and water that’s underground in soils and rocks. It includes the water that’s in the atmosphere as clouds and vapor.
If you could put all that water together – like a gigantic water drop – it would be 1,500 kilometers (930 miles) across.
Answer:19. He says that he’s been really tired since several weeks ago. 20. A friend of us is going to pick us up at the airport. 21. I’ve worked like a waiter in the past, but I wouldn’t want to do it again. 22
Explanation:
External
Stimuli are anything that causes arousal or enables an object to respond or react.
There are many different kinds of stimuli for which is different for every organism, for example, water, light and carbon dioxide are three stimuli and materials needed for photosynthesis in plants to manifest.
<span>In humans, we have nutrients or food, oxygen and water for us to survive. These are stimuli, eyes need light as a stimuli for it see and function. Nasal receptors needs smell as stimuli caused by molecular reactions of an object as a stimuli. And others. </span>
Chemical energy is the answer to your question
