Part of nixon’s officials methods of keeping tabs on the opposition was conducting:
a. polls
c. surveys
b. wiretaps
d. seminars

The answer is letter c. wiretaps.  Nixon’s aides were caught at a Democratic office which started the Watergate Scandal where he taped phone calls to find out what people were thinking.  As a result, many government officials and employees were arrested.  Rather than be impeached, Nixon chose to resign.

loess contribute to the flooding of rivers by providing the silt that is washed into rivers and constantly raises the bed of the rivers. this elevation above the surrounding flood plains and dams allow the river to overwhelm the dams and flood thousand of square miles of neighboring flood plains.

fir trees are found in areas with cooler climates. fir trees have needles for leaves and remain green year-round.