Question

select the two substances that would be most necessary for life as we know it to develop on another planet. carbon chlorophyll helium nitrogen water

Explanation:

Carbon is a key - element for organic compounds which are the basis of life. Water is essential for many biochemical reactions and provides a medium for life processes. Chlorophyll is mainly for photosynthesis in plants on Earth and not as fundamental as carbon and water for the start of life. Helium is an inert gas and not directly necessary for life - development. Nitrogen is important but not as crucial as carbon and water for the initial development of life.

Answer:

carbon, water