Environmental Science
Frost forms when:

The dew point is 32oF or below.
Objects on the ground cool below the dew point temperature.
Water vapor changes into ice without first becoming a liquid.
All of these

ANSWER DOWNLOAD EXAMIANS APP

Environmental Science
Low clouds retard surface cooling at night better than clear skies because:

The water droplets in the clouds reflect infrared energy back to earth
The clouds start convection currents between them
The formation of the clouds releases latent heat energy
The clouds are better conductors of heat than is the clear night air
The clouds absorb and radiate infrared energy back to earth

ANSWER DOWNLOAD EXAMIANS APP