What problem did the crew of Biosphere 2 face? A.
A virus from one of the animals
B.
A loss of oxygen
C.
One of the crew members developed cancer
D.
The crew ran out of food.

b and d

Explanation:

The Biospherians had to break into a three-month supply of food that had been secretly stored away before the doors had closed. Then Biosphere 2 began to lose oxygen because the soil had spawned an explosion of oxygen-gulping bacteria. The crew felt as if they were living at 14,000 feet.

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.