Which of the following is a good way to reduce salinization?

two things I don't see the options

and

I would say build a wall  

Using rainwater instead of groundwater on crops.

Explanation:

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.

answer: 21

step-by-step explanation:

divide 630 by 30. 30 goes into 630 21 times