Which one is the answer

One of the brightest comets of the 20th century was comet hyakutake, which passed close to the sun in early 1996. the orbital period of this comet is estimated to be about 30,000 years. find the semi-major axis of this comet’s orbit. compare it to the average sun-pluto distance and to the distance to alpha centauri, the nearest star to the sun, which is 4.3 light-years distant.

Name the two rivers that run through the fertile crescent. how were the rivers both positive and negative to societies of the fertile crescent?

Scientists believe that differences in cause hot, plastic-like rock in the asthenosphere to rise toward earth's surface. a. density c. weight b. magnetism d. composition c. conduction. d. density.