According to the speaker, what happened in the U.S. in the 1940s around the time of the Second World War that affected the popularity of the regionalist art

A．The populations of small towns increased rapidly.

B．Art critics in cities began to take notice of regionalism.

C．Some regionalist painters began a new art movement.

D．Society became more internationally focused.

在现代市场经济活动中，要求人们共同遵守的基本法则是（）。

A.服务群众

B.诚实守信

C.物美价廉

D.遵纪守法