The first red scare began in 1917 and lasted until about 1920. it was caused by a fear of anarchists and
a.
japanese spies.
b.
communists.
c.
german spies.
d.
fascists.

communists

Explanation:

As WW1 was ending, a fear driven anti communist movement, known as the first red scare, began to spread across the USA

incident infrared radiation is blocked. visible and ultraviolet radiation heat   earth.

earth radiates infrared radiation. infrared radiation is blocked and heats earth. visible and shortwave radiation heat earth.

earth radiates longwave radiation

longwave radiation is reflected downward longwave radiation heats earth