How long does the Proterozoic Eon last for? 541 million years
1,500 million years
1,959 million years
543 million years

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.

What factors of japan’s geography make it necessary for it to import so many goods?

Read the article titled "castro resigns." why did the us impose trade sanctions against cuba in 1962?