Answer:
1st question is because of co2 co2 is important for plant to grow so that's why people say plants grow more when people are talking Plants do need CO2, but they also need water, nitrogen, and other nutrients. Increase one of these without increasing the others and there's a limit to how much the plants will benefit.
Explanation:
2nd question
Humans consume around 50 liters of oxygen per hour and each plant leaf gives off about five milliliters of oxygen per hour. so im not really sure about the 2nd question
