下列诗句描述的气候现象,出现在长江中下游地区的是( )
A:天无三日晴,地无三尺平
B:早穿棉袄午穿纱,围着火炉吃西瓜
C:千里冰封,万里雪飘
D:黄梅时节家家雨,青草池塘处处蛙
已知f(x)=sinxsin(x+π6),x∈-π3,π3,则f(x)的最小值为____
They often talk __________ their study in the evening.