Why do scientists consider hiv to be an emerging virus? a) hiv infected humans long before the 1980s, but it has now mutated to a more deadly form. b) hiv mutates rapidly making the virus very different from hiv in the early 1980s. c) hiv suddenly became apparent and widespread in the 1980s. d) hiv is now starting to cause diseases other than aids, such as rare types of cancers and pneumonias.

In summing we use which law of motion

Last 5 benefits of physical activity and identify each benefit as either a physical mental and emotional or social benefit

Lyme disease is caused by a bacterium transmitted to people by deer ticks. deer ticks are almost never born infected with the bacterium, but they can pick it up from feeding on an infected host in any of the tick's three successive stage of development: larva, nymph, adult. once infected, a tick remains infected through any subsequent developmental stages, but since a tick feeds on only one host in each stage, it follows that . people can be infected only by being bitten by a tick that is either in larval stage or in the nymph stage b. people cannot be infected by a tick that picked up the lyme disease bacterium in the adult stage c. it is not possible for a person to be infected by a tick that is in the nymph stage or by a tick that was infected with the bacterium while in the nymph stage d. people infected with the lyme disease bacterium cannot transmit bacterium to adult deer ticks e. only deer ticks that are adults can transmit the lyme disease bacterium to people