Dark clouds are a of rain while a smile a of friendship.
A. sign; gesture
B. gesture; sign
C. sight; method
D. make; way
网友回答
(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.