For the fear of someone not believing them and maybe for the protect of the abuser not going to jail.
Think about how it would affect your future if you got caught. Some employers may not even higher you because under your record it shows "underaged drinking." If offered alcohol, you can make up lies saying "It makes me sick", or "My parents test me every month", also you could say "Not in the mood for drinking tonight".
Answer:
Option). about 20 percent of the calcium ion required for contraction comes from outside the cell.
Explanation:
Calcium ions play an important role in cardiac muscle physiology. Calcium ions influx is responsible for plateau phase after depolarization. Calcium ions also play role in muscle contraction with the help of troponin (regulatory protein).
For contraction, about 20 percent of calcium ions are supplied from outside of the cell, while rest of the calcium ions are released from SR (sarcoplasmic reticulum).
Thus, the correct answer is 'forth option.'