What does 3.1 times 10^34 molecules of water weigh?

Help it’s urgent

Iknow the answer is a but i don't know why

Brainliesttt me asap! the below reaction can be categorized as more than one type of reaction. which reactions are these, and what are the types of reactions?

14. many depressants reduce small muscle control, making it harder for a. you to steer b. your mind to consider complex problems c. the eye to scan, focus, or stay still d. the kidneys to filter alcohol out of the bloodstream