The Sun’s energy output, called brightness, varies by ____ with sunspot activity
a. ?less than 1 percent
b. ?about 2 percent
c. ?about 5 percent
d. ?about 10 percent
e. ?more than 15 percent
ANSWER: a
You might also like to view...
Which of the following set of surface conditions would produce a convective cumulus cloud with
the highest base? a. air temperature 40 oC, dew point 30 oC b. air temperature 25 oC, dew point 10 oC c. air temperature 35 oC, dew point 10 oC d. air temperature 45 oC, dew point 25 oC e. air temperature 25 oC, dew point 5 oC
Mudflows are ________ likely to occur in areas not protected by vegetation.
A. just as B. less C. more D. Mudflow occurrence is not related to average rainfall or vegetative cover.
The largest river (in terms of discharge) in the US is the Mississippi River.
a. true b. false
Active periods in a volcano's history
A. always begin with a nuée ardente. B. typically involve only one significant eruptive phase lasting days or, at most, a few weeks. C. may occur at intervals of hundreds or thousands of years, with quiet periods in between. D. All of the choices are correct.