What is the densestvpart of the earth?

Can someone list any possible solutions to air pollution ?

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.

When you imagine how you'll get from your house to the store, you are a. mental projection b. mental map c. piagetian projection d. cognitive load