Which of the following statements is true? 1.Extinction speeds up the evolution of other species.
2.Earth has only experienced one mass extinction in its history.
3.Speciation is caused by a reduction in gene flow.
4.Genetic diversity can be increased by genetic drift,

The table presents the average day and night temperatures in five cities. it also reveals whether a city receives substantial rainfall (wet climate) or little rainfall (dry climate). which city’s rocks are likeliest to experience frost wedging, and why? a) city a because the consistently subzero temperature would prevent water from melting b) city b because it is a wet region and the temperature fluctuates around the freezing point c) city c because it receives plenty of rain fall and the weather is moderately cool d) city d because the hot and dry weather would cause rocks to absorb water