Which undefined term is used to define an angle?

The prevailing climatic type in the southeastern part of the usa, western europe, southern brazil and northen argentina is the mid-latitude or: a)humid temperate b)humid cold c)semiarid moderate dry d)summer savanna.

When studying the calumet region of illinois and indiana alfred meyers noted four stages of development as new groups occupied this land in stage 2 farmers used the land primarily to grow food for their familes and their small communities

Distance that the transcontinental railroad covered from omaha to san francisco.