“最近怎么样?” 英语怎么打招呼?what's up?

“最近怎么样?” 英语怎么打招呼?what's up? 别人打招呼说what's up?我该怎么回话/ 如果有人打招呼（注意是打招呼的时候）问what's up 我要怎么回答? 当有人跟你打招呼说 what's up时怎么回答? 如果别人问你what's up/what's going on 这类打招呼的话你需不需要回答?怎么回答? 跟美国外教打招呼说What's up会不会不礼貌? 两个外国人见面之后打招呼,说“Hey,what's up! 美国人打招呼的What's up,What's happening,How are you doing,What's g s'up 能不能表示问候或打招呼的意思?跟what's up有什么区别? 对方问你“what's up?（打招呼,问好）”能不能回答not so good? what“s up与what“s going on都可以用来打招呼吗?与how are you一样吗? 初次见面,英语怎么打招呼