Uhmtell me why banned me for 2 days...and now i got my account backdid they do a update or sum bc im starting to get rlly annoyed smh

Why is the first step in responding to life-threading situations to assess the situation?

Health and cardio respiratory fitness occurs when the heart is working, at minimum, 50 percent of heart rate reserve. true or false

You isolate an infectious substance capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, viroid, or prion. you have four methods at your disposal to analyze the substance and determine the nature of the infectious agent.i. treat the substance with enzymes that destroy all nucleic acids and then determine whether the substance is still infectious.ii. microscope.iii. culture the substance on nutritive medium, away from any plant cells.iv. treat the sample with proteases that digest all proteins and then determining whether the substance is still infectious.if you already know that the infectious agent was either bacterial or viral, which method(s) listed above would allow you to distinguish between these two possibilities? a) ib) iic) ii or iiid) iv