Give 3 tips for properly and effectively using hand sanitizer

Rub your hands together gently. Be sure to cover the surfaces of both of your hands, including fingers and around your finger tips and nails.

You should also rub in the sanitizer about 2 inches (0.051 m) up each wrist.

When using hand sanitizer, make sure to take off any jewelry that your wearing. So you can get under the jewelry, and you don't want any bacteria growing there.

Explanation:

1. when you come home from school, supermarkets, ect.

2. when you have someone visit your house

3. when you touch things that were dirty a.k.a  when you hands are dirty

i think your answer is c. measurement system in which the medication dosage was calculated.