Answer:
Organ
Explanation:
Cells work together to make tissues, tissues work together to make organs, organs works together to make the organ system, and the organ system works to help the organism stay alive and do all of the physical stuff._.
Answer:
I think It is an organism
Answer:- A.
and 
Explanations:- In general, 
In acid-base reaction the acid gives hydrogen ion and the base gives hydroxide ion and these ions combine to form water. Rest of the ions from acid and base combine to form the salt.
Nitric acid breaks to give hydrogen ion and nitrate ion. Similarly, NaOH breaks to give sodium ion and hydroxide ion. Since, hydrogen ion and hydroxide ions form water, the sodium ion and nitrate ion forms the salt, sodium nitrate.
The reaction is shown as:

So, the right choice is A.
a. Radiant energy is converted to electrical energy.
Why by Mimiwhatsup: Solar panels are a form of radiant energy. When solar panels are used to provide power, then solar energy (radiant energy) is been converted to electrical energy.