-I will go to the countryside to see my grandmother this afternoon, so I can't go swimming with you.
-___________.
A:It's my pleasure
B:You are welcome
C:What a pity
D:Sure, I am
某商品经过连续两次降价,销售单价由原来100元降到81元.设平均每次降价的百分率为x,根据题意可列方程为( )
解释加线的词,并从《看云识天气》找出与之相呼应的句子。
姿态万千: 变化无常: