All living things must fight to stay alive.They have to feed on something and at the same time avoid being eaten.Therefore they have to solve this big problem of staying alive in their own way.
The danger of being eaten in the sea is great.Those plants and animals that do survive usually reproduce very fast and in great numbers.
Certain sea animals have defensive devices(装置)which help them to survive.The jelly fish have poisonous tentacles(触角)which are used for attack and defence.
Another method of survival which sea plants and animals use is disguise(伪装).They usually have the same colour as their surroundings.
In order to stay alive, animals need to have good senses.Fishes have sharp eyes.Almost all animals are sensitive to touch.Fishes judge movements in the water by means of their lines.Fishes and other sea animals can hear well and many of them can make different types of warning sound.
(1)
What is the greatest problem that the living things face?
[ ]
A.
They have to eat other things.
B.
They have to fight not to be eaten.
C.
They have to live on in their own way.
D.
They have to live in the sea.
(2)
How many kinds of animals in the sea have more chances to survive?
[ ]
A.
One.
B.
Two.
C.
Three.
D.
Four.
(3)
Jelly fish is an example of animals ________.
[ ]
A.
who can reproduce very fast
B.
who can protect themselves from being attacked
C.
who can change their colours
D.
who have very good senses
(4)
Which of the following is NOT mentioned to help animals survive?