Answer:
The doctor remained placid during the surgery because he was very focused on performing the operation correctly.
Driving in a car is the predominant method of travel because of how convenient, flexible, comfortable and fast driving in one can be.
It took some practice for the group to sing in unison because one of the members kept interrupting everyone else.
The nation was impoverished because most crops and livestock died, causing famine and a huge loss of careers.
Those clouds on the horizon appear ominous because there have been natural disasters near the area lately.
Step-by-step explanation: