Paleontologists have found evidence that after a major extinction occurs, there is no particular pattern of speciation many new species often appear at about the same time a new species evolves to replace each species that became extinct most species move away because they cannot adapt

The correct answer is B. Many new species often appear at about the same time

Explanation:

During Earth's history there have been at least five major extinction during which the biodiversity of Earth declines sharply, this includes the end-Cretaceous extincion, the end-Triassic, the end-Permian, the late-Devonian and the end-Ordovician extinction, although due to limited inforamtion and diferent parametes to categoriza a major extinction it is believed there have been more major extinctions.

In all of these cases, after a major extinction occurs the species that survive often diversify and new species of the same kind appear at the same time which implies a peak in speciatio, for example, after the last major extinction mammals experienced a peak in speciation which has been proved through fossils found by paleontologists.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.