How can scientists test their ideas about the origin of the universe if they can't physically interact with or study it

Why did richard and mildred loving have to go to washington, d.c. to get married?

Which answer best describes the u.s. national road? it ran from atlanta to baltimore and followed the railroad. it ran from new york to chicago and was made from wooden planks. it ran from massachusetts to ohio and ran parallel to the canal system. it ran from maryland to illinois and was made using macadam construction.

One drawback of voluntary trade is that it a.requires two groups to use a common language b.can make one group dependent upon another for necessary goods c.doesn't occur unless there is a shortage of goods for at least one group d.forces groups to rely on themselves to produce all the goods they need