An electromagnet is created by A. putting a piece of soft iron in an outlet.
B. brushing a piece of steel with a soft cloth.
C. running electric current through a coiled, conductive wire.
D. rubbing two pieces of metal together quickly.

A. putting a piece of soft iron in an outlet

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.

the answer is a and have a great day