What is the wavelength of an electromagnetic wave that has a frequency of 3 kilohertz?
A) less than 1 km
B) 1 km
C) more than 1 km
Question 2
Which best shields you from sunburn when at the beach?
A) a cloudy day
B) a sheet of glass between you and the Sun
C) frequent turning of your body
D) all of the above
E) none of the above