Pacemakers maintain the heartbeat in people who suffer from certain defects. The function of an artificial pacemaker is to send electrical impulses that will contract the heart muscles and regulate the pumping of the heart. Which condition could be corrected by a pacemaker? A.
The individual’s sinoatrial node ceases to function.
B.
The individual’s central nervous system fails to signal the heart to contract and relax.
C.
The individual’s arteries are blocked.
D.
The valves in the individual’s heart cease to function.

Which mantle is under the crust the upper mantle or the lower mantle i think it's upper let me know if i'm right

Factors that can increase mutation rates a. high temps b. low temps c. food additives d. uv rays

This map shows how climate change might affect precipitation patterns in the great plains of the united states by the end of this century. brown shoes a decrease in percipitation, and blue shows an increase. the maps differ based on the predictive levels of green house emissions. the maps shows that northern area should get a. more pracipations regardless of emmissions b. less pracipation, regardless of emmissions levels c. more precipitation, but only when emission levels.southern areas show a. more pracipations regardless of emmissions b. less pracipation, regardless of emmissions levels c. more precipitation, but only when emission levels.to use these maps to prepare for natural disasters in the great plains, scientist need to ask? a. how many tons of emissions were used at the basis of the map.b. which types of fossil fuels are used in the great plains c. if you think the above is wrong it's probly c the question is cut off