Nearly three-quarter of the Earth is covered with water. The【B1】______of the continents, especially in the temperate zones, is very much【B2】______by the oceans around them. The areas【B3】______the sea have a "【B4】______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.【B5】______after heavy rain, the pavements in a city do not take【B6】______to dry because the rainwater evaporates into the air. On a warm dry day it e-vaporates very rapidly, as warm air can absorb more【B7】______than cold air.【B8】______at any particular temperature, the atmosphere can hold only a certain【B9】______amount of water vapor. The air is then saturated,【B10】______a sponge that cannot hold any more water. The lower the temperature, the【B11】______water vapour is required to saturate the air. All over the surface of the Earth, millions of tons of water are evaporating every second,【B12】______in the air into drops so small that it【B13】______thousands of them to make a single raindrop. It is these【B14】______droplets that make clouds. When clouds roll in from the sea over the warmer land, they are forced to【B15】______and become cooler in the colder upper atmosphere. As the air【B16】______it may pass through its【B17】______point and then some of its water vapor turns to rain. Day in, day out, the【B18】______water circulates between the air and the land: rivers evaporate to make clouds, clouds make rain, rain makes rivers which【B19】______run into the sea. This is called the rain【B20】______.