The lowest temperature is found near the top of which atmospheric layer? a. troposphere b. stratosphere c. mesosphere d. thermosphere

Which nucleotide component contains nitrogen

Who discovered tuberculosis bacteria?

When it is summer at the south pole, a. the northern hemisphere is tilted toward the sun. b. the southern hemisphere is tilted away from the sun. c. the northern hemisphere is tilted away from the sun. d. both the southern and northern hemispheres are tilted toward the sun.