Why did progressives favor the direct primary
a) it gave parties opportunities to extend the campaign cycle.
b) it let voters determine the candidates rather than caucuses
c) it allowed women and minorities to vote on party candidates as well.
d) it was more cost- efficient than the caucus.

the qing dynasty placed strict limits on foreign merchants' ability to trade in china.

incident infrared radiation is blocked. visible and ultraviolet radiation heat   earth.

earth radiates infrared radiation. infrared radiation is blocked and heats earth. visible and shortwave radiation heat earth.

earth radiates longwave radiation

longwave radiation is reflected downward longwave radiation heats earth

i think the answer is d. good luck.