Generally speaking, the water pollution in cities is more serious than __________ in the country.
Exactly ________ the potato was introduced into Europe is uncertain, but it wa s probably around 1565.
there is no water and air on the moon, is there?_____________________
Water boils __________ if there is a cover on the pan.
The water temperature surrounding the kelp beds is __________ than that around reefs.
Another natural ____________ that contributes to the welfare of the country is water.
When the temperature is below zero， water will _______.
The land is affected by a ________ and the cattle are dying fast for lack of drinking water.
254. Mean high water is the average height of ____
We have been given the __________ that the water is safe to drink. (reassure)
The glass of water is too hot, I prefer some cold water _____ .
11. To predict the actual depth of water using the Tide Tables，the number obtained from the Tide Tables is _____.
Rainfall．is the main__________of water supply in that area．
Living in the centra]Australian desert has its problems，__________obtaining water is not the least．
The amount of water used in the manufacturing process is enormous, but the amount wasted is______.
We can______the pipe out with hot water, if it is blocked.
__________most of the earth‘s surface is covered by water， fresh water is very rare and precious．
The function of the sentence "Water boils at 100 degrees Celsius." is_________.
The two elements ,______water is made up are the gases oxygen and hydrogen.
The valve that prevents water from backing out of the boiler into the feed line is the______.
One of the most important lakes in the United States is______, which is the largest fresh water lake in the world.
The two elements______water is made are oxygen and hydrogen.
The distance between the surface of the water and the tidal datum is the______．
‘How much water is left in the bottle？’ ‘______’
