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All animals, including fish, need water to survive. Most freshwater fis absorb water through their gills, while most saltwater fish drink water and filter out the salt with their gills.
Fish use water to balance the salt content in their bodies. Freshwater fish usually try to get rid of water because it dilutes the salt content in their bodies.Saltwater fish conserve water to prevent salt from building up too much. Salmon,which live in both fresh water and the ocean, absorb water while in rivers and lakes and drink water while in the ocean.
Word List
gills : the parts of a fish that help it breath
filte : take in while keeping unwanted things out
conserve : save
prevent : to stop
dilute : to make something weaker
You Practice
1） What do all these things need? Write the word.
The dog needs_______________.
The fish needs_______________.
The plant needs ______________.
Some fish live in fresh water . A lake and a river are fresh water. Some fish live in salt water . The ocean is salt water.
2） Complete the sentences.
A lake and a river are ___________________ water.
An ocean is _________________ water.
3） What do all living things need? Circle the word.
gills water mouth
4） Read each sentence. Write Yes or No.
____ 1） Fish live in water.
____ 2） Fish use gills to eat.
____ 3） A river has salt water.
____ 4） The ocean has salt water.
5） What's the word? Find the correct words in the reading.
a. This is a kind of fish: s _ _ _ _
b. These help fish breathe: g _ _ _
c. This water has no salt: f _ _ _ _ w _ _ _ _
d. This means to keep living: s _ _ _ _ _ _
e. This means to make something go away: g _ _ r _ _ o _