Every population has limiting factors
Answer: i think is chemical is correct answer
Answer:
Concerts, sports games, and political rallies can have very large crowds. When you attend one of these events, you may know only the people you came with. Yet you may experience a feeling of connection to the group. You are one of the crowd. You cheer and applaud when everyone else does. You boo and yell alongside them. You move out of the way when someone needs to get by, and you say “excuse me” when you need to leave. You know how to behave in this kind of crowd.
It can be a very different experience if you are travelling in a foreign country and find yourself in a crowd moving down the street. You may have trouble figuring out what is happening. Is the crowd just the usual morning rush, or is it a political protest of some kind? Perhaps there was some sort of accident or disaster. Is it safe in this crowd, or should you try to extract yourself? How can you find out what is going on? Although you are in it, you may not feel like you are part of this crowd. You may not know what to do or how to behave.
Explanation:
I don't have enough knowledge about this hope it helps
（C)因為碳水化合物在初步的消化系統中就會將其分解為簡單的醣類使人體方便吸收代謝
I’m pretty sure the answer is air pollution
