Answer:
i think glucose and oxygen
Explanation:
Answer is: a secretary smokes a cigarette in a crowded break room.
External cost Is when consuming a good or servise imposes a cost to a third party. In this case, smoking affects other people in break room, causing pollution and health related problems.
A is the answer. You would need soil with different amounts- including no amount- to determine how the fertilizer affects the plants
Since you are measuring the height a ruler would be a good idea as well.
