Nearly three-quarter of the Earth is covered with water. The (1) of the continents, especially in the temperate zones, is very much (2) by the oceans around them. The areas (3) the sea have a " (4) climate", with rather cool summers and warm winters. The interiors, far from the sea, have a climate with extremely hot summers and cold winters.
Rain comes from the evaporation of rivers, seas and lakes. (5) after heavy rain, the pavements in a city do not take (6) to dry because the rainwater evaporates into the air. On a warm dry day it evaporates very rapidly, as warm air can absorb more (7) than cold air. (8) at any particular temperature, the atmosphere can hold only a certain (9) amount of water vapor. The air is then saturated, (10) a sponge that cannot hold any more water. The lower the temperature, the (11) water vapour is required to saturate the air.
All over the surface of the Earth, millions of tons of water are evaporating every second, (12) in the air into drops so small that it (13) thousands of them to make a single raindrop. It is these (14) droplets that make clouds. When clouds roll in from the sea over the warmer land, they are forced to (15) and become cooler in the colder upper atmosphere. As the air (16) it may pass through its (17) point and then some of its water vapor turns to rain. Day in, day out, the (18) water circulates between the air and the land: rivers evaporate to make clouds, clouds make rain, rain makes rivers which (19) run into the sea. This is called the rain (20) .
A.because
B.for
C.like
D.since