Answer:
This is nuclear fusion that happens in the core of stars. This is the process of converting hydrogens into helium. It is also converting mass into energy as the starting mass is higher than the finishing one, that missing mass is released as energy.
Explanation:
It is called blind. a condition in which the participant is not aware if he/she is in the experimental or control group
Answer: Pigeon and duck.
Explanation:
From that side of the tree, you can see that the pigeon and the duck are closest together in the tree than the other organisms in the other options.
