During select 1)photosynthesis 2)carbon dioxide
3)increase
4)decrease

Plant take in
The atmosphere to

Plants take in carbon dioxide, water, and sunlight in order for photosynthesis to occur. In return plants produce oxygen which is sent out of the plants, and glucose (energy) which is used by the plants to survive.

Airplanes usually fly in the lower part of the stratosphere - there is nearly no water vapor and it's very dry, so it to avoid big turbulences. it's about 8-10 kilometers above ground (depending on weather conditions, region etc.)