Cold, dry air affecting the northern united states in winter often comes from
a. maritime polar air masses.
b. maritime tropical air masses.
c. continental polar air masses.
d. continental tropical air masses.

Look at the diagram showing the different wavelengths in sunlight. which statement describes electromagnetic waves with wavelengths greater than 700 nanometers? they take the form of heat. they can cause skin cancer and sunburn. they are some of the shortest waves. they can be seen by human eyes as visible light.