Alarge farm is located in your watershed suggest two precautions the farmer could take to protect the river next to this

The farmer should limit their use of fertilizer and manage the waste of their animals.

Explanation:

This helps prevent pollution of the river.

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )

the device is called “ rocket engine”