Answer:
P wave
Explanation:
Electrocardiogram records the strength and timing of electrical activity in heart. As various regions of heart contract at different times and for different duration, the electrical activity is not constant and shows a series of rise and fall. There are three main components of ECG: P wave, QRS complex and T wave.
P wave indicates the beginning of electrical signal in the right atrium. The signal spreads in both right and left atria which leads to their contraction. As a result, blood is pumped into the ventricles and rest of the process occurs.
I think Is Rovers they helped explore other planets such as mars
Answer:
true
Explanation:
By experimentating your testing a theory or hypothesis based on certain criteria to see if your theory is correct. By experimentating you record data to back up your claims.
The theory or hypothesis is just your guess of what may or may not happen based on the criteria your wanting to prove.
