Which of these are the two major sources of nitrate pollution in rivers?

Rivers can be polluted by nitrates because the fertilizers in the field that contain nitrates are washed into the river because of rain and flooding. Other source of nitrate pollution in the rivers is the mixing of sewage which contains human and animal wastes.

I’m going to go with b!

1) clean up you lab area2) dispose of the chemicals as instructed by your teacher3) put everything back where it belongs unless your teacher tells you otherwise4) dispose of gloves5) wash hands with soap and water