Secondary treatment uses to clean the water.
a. chemicals
b. microorganisms
c. screens
d. skimmers

Mario was conducting research regarding the treatment of aids victims using stem cells. he found a source that was written recently and the author was known. unfortunately, he could not determine if it had been peer reviewed.

What can friends provide to affect mental health positively? a)peer pressureb)challengesc)conflictd)com panionship

Why is important to keep your health triangle balanced?