Answer: When the plant has enough water in its cells the guard cells swell up and open the stomata. When the plant isn't getting enough water the guard cells can't swell and the stomata stay closed, so the plant doen's lose water. But if the stomata are closed photosynthesis can't happen and eventually the plant might starve.
Explanation:
I think its C. global warming
because the other one directly threats aquatic bio diversity while global warming doesn't just affect aquatic biodiversity
Answer:
B. They last much longer than traditional lightbulbs
