问题补充:
Dark clouds are a of rain while a smile a of friendship.
A. sign; gesture
B. gesture; sign
C. sight; method
D. make; way
答案:
(答案→)A. sign; gesture
B. gesture; sign
C. sight; method
D. make; way
解析:句意为:乌云是一种下雨的迹象,而笑容是一种友好的姿势语言,表示“迹象”,用sign,而表示示意的动作,姿态用gesture.