Not Timed Save Progress Progress has never been saved 1) The earth's magnetic field influences (2.5pts) O comets meteoroids. O eclipses. auroras. 2) The source of the sun's energy is (2.5pts) radioactivity. nuclear fission. O nuclear fusion. O combustion. 3) Sunspots (2.5pts) O are dark clouds floating in the solar atmosphere. occur at random intervals. O cause solar eclipses O are cooler than the rest of the solar surface. 4) (2.5pts) The expansion of the universe apparently is currently speeding up has come to a stop has always occurred at the same rate O currently slowing down 5) The two chief elements in the sun are (2.5pts) hydrogen and helium. O hydrogen and oxygen. oxygen and nitrogen. carbon and iron. 6) Nuclear reactions in the sun's interior convert (2.5pts) O hydrogen into helium. O , helium into hydrogen. carbon into nitrogen. uranium into plutonium. 7) The distance of a star from the earth can be found (2.5pts)