good land againThey want to bring water to the desert,so people can live and grow foodThey are learning a lot about the desertBut more and more places of the Earth is becoming desert all the timeScientists may not change the desert in time．
Why is more and more land becoming desert?Scientists think that people make desertPeople are doing bad things to the earth
Some places on the earth don
't get much rainBut they still don't become desertThis is because some green plants are growing thereSmall green plants and grass are very important to dry placesPlants don't let hot sun make the earth even drierPlants don't let the wind blow the dirt awayWhen a little rain falls,the plants hold the water．Without plants,the land can become desert much more easily
(1)
Desert ________
[ ]
A．
gets not much water
B．
never has any plants or animals in it
C．
both A and B
D．
can all be turned into good
land before long
(2)
Small green plants and grass are
very important to dry places because ________
[ ]
A．
they don
't let the sun make the earth much drier
B．
they don
't let the wind blow the earth away
C．
they hold the water
D．
all the above
(3)
Land is becoming desert little by little because ________
[ ]
A．
plants can
't grow there
B．
there is not enough water
C．
people are doing bad things to the earth
D．
scientists know little about desert
(4)
After reading this passage,we learn that ________
[ ]
A．
plants can keep dry land from becoming desert
B．
it is good to get red of the grass in desert
C．
all places without much rain will become desert
D．
it is better to grow crops on dry land than to grow grass
