Answer:
A hill is a part of land that rises higher then everything surrounding it its like a little bump in the earth. Mountains have less steep and not as high but a hill will usually have and obvious summit which is its highest point
d is correct answer of a question
Answer:
Weather conditions
Explanation:
Food can be limited based on location, however, scientists can control what kind of food it is. Soil can be tested and experimented on. There can be a lot of it and different kinds. Space is fought over because of territories and is limited compared to how many people and animals there are. Weather is not something that can be controlled in an experiment since it is sporadic.
Low blood cells is the answer that I have I got this right when this was my question hope this helps!!