Answer:
C. Trees
Explanation:
Trees can be replanted and we can grow more, even though it takes a long time this still makes them a renewable source.
Answer : A metal in group 16 of the periodic table can become a chemically stable ion by gaining 2 electrons.
Explanation :
The group 16 element are oxygen, sulfur, selenium, tellurium and polonium.
The general electronic configuration of group 16 elements is, 
As we now that there are total 6 electrons in p sub-shell. So, a metal in group 16 can become a chemically stable ion by gaining 2 electrons.

Hence, a metal in group 16 of the periodic table can become a chemically stable ion by gaining 2 electrons.
Answer:
3) The correct answer would be the third option.
Enzymes are biocatalysts which increases the rate of a biochemical reaction is decreasing the activation energy required by the reaction.
The substrate binds to the active site of the enzyme to form an enzyme-substrate complex. It is then converted to enzyme-product complex. Lastly, the product is released and the enzyme is ready for a new cycle of reaction.
4) The correct answer would be cohesion.
Cohesion or cohesive force refers to the attractive force by which like-molecules are stick together.
For example, water molecules are stick together to form droplets.
Answer:
A animal 2b has no cell wall