Answer:
D-T helper cells kill virus infected cells
Answer:
They regulate some aspects of production and distribution
Explanation:
Hope it helps! ^w^
Answer:
Around 4.1 billion years ago, the first single celled life form appeared on Earth
Definitely 4 Play control environment temperature
Umm... I believe you haven't shown the answers? But anyways, a carrying capacity is the maximum amount of organisms that can live within an environment. Once they reach carrying capacity, they typically begin to die off because there isn't enough food to provide to everyone.
