1 is c 2 is b 3 is 1 d 4 is a
Explanation:
The given reaction equation is as follows.
+ ___ 
As there is release of one hydrogen which shows that mass number has increase by 1 on the product side.
Therefore, particle
must be added in order to balance the given reaction equation.
Hence, the complete reaction equation will be as follows.

Answer:
C
Explanation:
Fresh water fish need freshwater.
Explanation:
I don't know sorry ok I have some work so I m sorry