Which of the following is not a threat to coral reefs?

answer:

coral

step-by-step explanation:

coral reefs don't hurt themselves

answer: planting trees

reduce your carbon footprint.

using   less

using organic fertilizer to avoid chemicals running into the ecosystem.

i guess these are some ways that are not harmful to coral reefs : =)

50*10 is greater

step-by-step explanation:

if you add the zero from 10 to 50, it will give you a bigger number.

the first one, all those points on the line just make a strait line.