Explain how economic, social and political changes
have contributed to
changes in fertility rates in
many parts of the world!

Which of the following statements about the migration of workers to other countries is false?

Gemstones are commonly found in pegmatites, which are igneous rocks that are a. exceptionally mafic b. exceptionally coarse grained c. exceptionally fine grained d. extrusive, forming from lava

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.