2 . Almost all animals need to sleep to stay healthy. But sleeping can also be dangerous because other animals ________ hurt those who are sleeping. So, we can find ________ many different ways of sleeping help them stay safe. You may be ________ by some of these way.
Some ducks sleep with just half of ________ brains. They often sleep in ________ line. The ducks at both ends help keep the group safe. They keep one eye open to watch for ________ . The ducks in the middle sleep ________ with both eyes closed.
Seals breathe air, but that doesn’t stop some of them from ________ underwater. They hold their breath and dive deep to sleep. Sleeping deep underwater ________ these seals stay safe from dangerous animals that hunt them near the surface.
Horses often sleep standing up. Their legs lock in place so they don’t fall ________ . If a horse is lying down, it takes a long time ________ up. A horse can run from danger more quickly ________ it is already standing.
A flamingo can sleep while standing on one leg. The standing leg locks so it says straight. ________ leg remains close to the flamingo’s body. Its head rests on its back.
Some seabirds can sleep while they ________ . These large birds spend most of their lives over the ocean. They are in danger on the water, ________ they are safe in the air. They fly for many hours without flapping (拍打) their wings.
Would you like to sleep how they sleep?
1.
A.need | B.may | C.must | D.should |
2.
3.
A.surprise | B.surprised | C.surprising | D.surprises |
4.
A.they | B.them | C.their | D.themselves |
5.
6.
A.danger | B.endanger | C.endangered | D.dangerous |
7.
A.deep | B.deeper | C.deepest | D.deeply |
8.
A.sleep | B.slept | C.to sleep | D.sleeping |
9.
A.help | B.helps | C.helped | D.is helping |
10.
11.
A.get | B.to get | C.getting | D.got |
12.
A.if | B.until | C.unless | D.though |
13.
A.Other | B.Others | C.The other | D.Another |
14.
A.will fly | B.flew | C.are flying | D.were flying |
15.