Do you know what the world\’s tallest animals are?How do they sleep and drink?
You may think it\’s difficult for them to sleep,but they have no such problems because giraffes don\’t often stop for a snooze（打盹）.As they are so tall that they can grow up to 18 feet,giraffes actually need the shortest sleep of all mammals（哺乳动物）,with an average（平均）of half an hour a day.When they sleep,they hardly lie down and sleep for minutes at a time,because it\’s difficult for them to get up again and it\’s dangerous in the wild（荒野）.But the giraffe in the zoo sleeps around 4 or 6 hours a day,mostly at night.It usually sleeps lying down.
Drinking water may be a problem for giraffes because their long necks are too long to reach the ground.To drink,they must spread their legs in an uncomfortable way,and in this way they will be easily caught by other animals like Africa\’s big cats.So,they get most of their water from the plants that they eat.They only need to drink water every few days.

（1）We can learn that giraffes in the wild sleep about ______every day.
A．thirty minutes
B．two hours
C．four hours
D．six hours
（2）From the passage,we know that ______makes other animals catch giraffes easily.
A．their height
B．the way they drink water
C．their size of their neck
D．the water they drink
（3）The main idea of the passage is about ______.
A．how long giraffes sleep
B．where giraffes can live
C．how giraffes sleep and drink
D．where giraffes can get water