Answer:
For most crops the saturation point will be reached at about 1,000–1,300 ppm under ideal circumstances. A lower level (800–1,000 ppm) is recommended for raising seedlings (tomatoes, cucumbers and peppers) as well as for lettuce production
Explanation:
(I do not take credit for the answer)
Are there suppose to be choices?
Answer:
I thinks is pollution
Explanation:
its the only one that makes sense