Why might television and newspaper advertisements be incomplete sources of information about candidates? O They are very expensive to produce.
They rarely reach the attention of voters.
They generally do not appear long enough.
O They show bias toward the promoted candidate.

D-they show bias toward the promoted candidate

Explanation:

the causes of the dust bowls were severe droughts,   lands became dry and hard, temperature was higher than usual, hot and dry conditions killed crops, high winds. because of those factors, the winds kicked up dry soil and created clouds of dust.

c. free trade can lead to low pay for workers in poorer countries.