Some American Indians cannot express the idea of time in their tribal languages This fact shows that_____________ ??

Some American Indians cannot express the idea of time in their tribal languages This fact shows that_____________ ??

A. their culture is still at a primitive stage
B. they have not yet reached the industrial stage of evolution when time is money
C. like all lower-class persons they focus on the present
D. time is not an important value in their culture

Experiments_______________?

Experiments_______________?

A. are conducted in both field and laboratory setting
B. involve the risk that people may modify their behavior
C. must involve control groups of some kind
D. all of the above