What is difference between grade and class​

Which of these is a controllable risk fator for disease

Which of the following represents a difference between viruses and viroids? a) viruses infect many types of cells, whereas viroids infect only prokaryotic cells. b) viruses have capsids composed of protein, whereas viroids have no capsids. c) viruses have genomes composed of rna, whereas viroids have genomes composed of dna. d) viruses cannot pass through plasmodesmata, whereas viroids can.

Which of the following choices is the most important to do before starting an exercise program? a. see your doctor b. talk to your friends for advice c. lift some weights d. measure your body fat