Ⅳ. 完形填空
When you turn on the tap in your house, water comes out. The water has
travelled
a long way. It comes from rain. The
way
that water gets to the tap in your house is called the "water supply".
Most of the water on earth is in the
ocean
. Ocean water has a lot of salt in it. We cannot drink it. Salt water makes us ill. But when the sun shines, it
heats up
part of the ocean. Some water rises up to make clouds in the sky. The more water rises up, the heavier and larger the clouds will become. The clouds will get so heavy and large that they will change colour from white to
grey
. The water will fall down into rivers and lakes
as
rain and travel back to the sea. This is called the "water cycle". We
use
half of the rain water that falls on earth.
There are parts of the world where there is
little
fresh water. In the Arab countries, salt water can be made safe to drink. This is done by freezing or boiling it. The salt is left
behind
and the clean water is then taken off. This process is very
expensive
, but in some areas this is the only way to get clean drinking water.
(
D
)16. A. pulled B. pushed C. rushed D. travelled
(
A
)17. A. way B. idea C. reason D. condition
(
B
)18. A. stream B. ocean C. river D. lake
(
C
)19. A. takes in B. gives off C. heats up D. cools down
(
B
)20. A. purple B. grey C. blue D. pink
(
C
)21. A. through B. with C. as D. by
(
B
)22. A. drink B. use C. buy D. make
(
D
)23. A. few B. much C. enough D. little
(
A
)24. A. behind B. alone C. off D. out
(
D
)25. A. rapid B. cheap C. simple D. expensive
