A. Let me see. I think it's a toilet for a pet(宠物).
B. Yes. I do. I like studying them.
C. Do you know anything about the public signs?
D. OK. What does that sign on the door mean?
在同一条等降水量线上,各点的 ____ 相等.
已知 x,y 是实数,且 x2+2i-2x+a-yi=0 (其中i是虚数单位),则 x+yi =____.