Before im how have scientist been able to determine the composition of earths layer? earth science

List three reasons people may begin using tobacco

Viruses ) manufacture their own atp, proteins, and nucleic acidsb) use the host cell to copy themselves and make viral proteinsc) use the host cell to copy themselves and then viruses synthesize their own proteinsd) metabolize food and produce their own atp

Explain why methicillin resistant staphlococcus aureus (mrsa) is more prevalent now than it was only 30 years ago. a. antibiotics cause mutations in staphlococcus aureus that lead to an increase in the number of methicillin-resistant strains. b. methicillin resistance causes an infection to spread more rapidly.c. frequent and inappropriate use of methicillin-type antibiotics has provided selective pressure that has resulted in an increase in the proportion of methicillin-resistant strains of staphlococcus aureus.d. diseases like aids have made people more vulnerable to infections from staphlococcus aureus.