Explain how an optimum PH level is maintained which is needed for enzymes to function effectively?

The cardiovascular system, which transports blood through the body, is a one-way system. select the best answer from the choices provided. t f

What should you not do when doing abdominal workouts? a. keep your chin off your chest b. keep your head aligned with the spine c. put pressure on your neck d. all of the above

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