Which of the following can be used to determine the compostion of a star?
a. line spectra
b. blackbody spectrum
c. the star's magnetic field
d. light from sunspots

Plants in the tundra biomes have had to adapt to live long periods of time without a. cool temperatures b. sunlight c. oxygen d. water

Which phrases describe oxygen's roles in earth’s atmosphere? check all that apply. allows fuels to burn forms clouds that produce rain is the gas that animals breathe is used by plants to produce food forms ozone that absorbs the sun's harmful rays

What are mountains that divide european russia from asian russia?