Use of English 
     Read the following text. Choose the best word or phrase marked A,B,C or D for each numbered blank.

     Nearly three-quarters of the earth is covered with water. Water heats up more slowly than land, but once it has become warm, it takes longer to_1_down. If the earth’s surface were entirely land, the temperature at night would_2_quite quickly and night would become cooler than the day, as it is on the moon. This does_3_happen in inland deserts, the temperate_4_, is very much affected by the oceans around them. The areas close to the sea have a “maritime climate”, _5_rather cool summers and warm winters. The interiors, far from the sea, have a_6_climate with extremely hot summers and cold winters. 
     Rain_7_from the evaporation of rivers, seas and lakes. Even after heavy rain the pavements in the city do not take long to dry_8_the rainwater evaporates into the air. on a warm dry day it evaporates very rapidly, _9_warm air can absorb more moisture than cold air. But at any particular temperature, the_10_can hold only a certain maximum amount of water vapor. The air is then saturated like a sponge that can not hold_11_more water. The lower the temperature, the_12_ water vapor is required to saturate the air.
     All over the surface of the earth, millions of tons of water are_13_every second, condensing in the air into drops so small_14_it takes thousands of them to make a single raindrop. It is these_15_ droplets that make clouds. When clouds roll in from the sea over the warmer land, they are forced to_16_and become cooler in the colder atmosphere. As the air cools sown, it may pass through its saturation point and_17_some of its water vapor turns to rain. Day in , day out,the_18_water circulates between the air and the land:rivers_19_to make clouds, clouds make rain, rain makes rivers which in turn run into the sea. This is called the rain_20_.
1.A.cool B.balance C.keep D.condense
2.A.rise B.loose C.miss D.fall
3.A.indeed B.not C. however D.ust
4.A.centers B.moisture C. fields D.zones
5.A.with B.instead of C. within D.owing to
6.A.maritime B.continental C.conventional D.normal
7.A.evaporates B.result C.comes D.restrains
8.A.though B.because C.while D.so that
9.A.where B.now that C.as D.as long as
10.A.climate B.atmosphere C.weather D.rivers
11.A.no B.some C.any D.much
12.A.more B.less C.fewer D.greater
13.A.heating up B.flowing C. evaporating D.moving
14.A.for B.that C.then D.yet
15.A.big B.enough C.tiny D.circulating
16.A.raise B.drop C.be cold D.rise
17.A.then B.already C.merely D.soon
18.A.running B.vapor C.evaporated D.same
19.A.evaporate B.try C.cool D.tend
20.A.saturation B.effect D.system D.cycle