Why has the power to regulate interstate commerce become such an important power of congress?

The continents of africa and south america used to "fit together” like puzzle pieces. about how far back in time would you have to go to find the formation of the atlantic ocean? 600 million years 430 million years 200 million years 90 million years

If a swimmer is traveling at a constant speed of 0.85 m/s,how long would it take to swim the length of a 50m olympic sized pool?

In the construction of a new housing development which factor of production can be categorized as land?