Why is it important to monitor the quality of air?

Because north america is in a it has a variety of biomes and climates. a. high latitude zone c. middle latitude zone b. middle longitude zone d. high longitude zone select the best answer from the choices provided a b c d

According to the earth science reference tables, during which geologic time period were the continents of north america,south america, and africa closest together?

According to the population pyramid, in 2000 china had about 120 million people in which age-group?