If SA node cells dont actually help pump blood, why does the heart need them?

Which shows a correct order of steps in the scientific method? develop a hypothesis, analyze data, draw conclusions, make observations develop a hypothesis, analyze data, make observations, draw conclusions make observations, develop a hypothesis, analyze data, draw conclusions make observations, draw conclusions, develop a hypothesis, analyze data.

Mary is 14 year old her resting heart rate is 70 beats per minute. calculate 50% of mary's maximum heart rate to fine her target heart rate

Which of the following methods had the highest risk of transmitting hiv? a) oral sex b) sharing needles c) sweat d) preseminal fluid