Which theory referred to the policy held by certain U.S. presidents, positing that the Communist takeover of Vietnam or Korea during their respective wars would lead to the fall of other Asian countries as well?

Congressional standing committees are best described as

A) specially appointed investigative bodies B) joint committees of the two houses of Congress C) committees created for each session D) permanet subject-matter committees E) advisory staff agencies

The simplest one of these is a visual rating. These are used to create measures of variables,

what are these? A) thermometer B) telescope C) scale D) weight