Thank you everyone! I love you with the power of one thousand suns! (that *may* not translate that well - just think of sun in the sky, it's powerful. imagine 1,000 of them, very powerful. that's how powerful my love is for all of you!)

打招呼嘛，你就跟他说：“哈喽啊！”就可以了。

1. hao a ,好啊；2.zui jin zen mo yang 最近怎么样；3. gan ma qu le 干嘛去了；4 qi se bu cuo 气色不错；5.you xin xian shi mei有新鲜事没？6. mei sha shi ba 没啥事吧。。。。。。

It depends.if you see your friends in a bad mood you may say 怎么了?if nothing goes wrong you just want to greet your friends you can say怎么样?but i think we seldom greet like that unless theres a specific situation.for example ,if i know my friends have been up to his paper,i can say"论文怎么样了?"

In fact ,many Chinese greeting each other in Chinglish "Halo"(Hello)哈喽、"Hai"(Hi)嗨,these are informal greets between friends. If your friends are from Beijing,you can greet him/her with"Yo,ni ya qi de zhen zao ah!"哟，你丫起得真够早啊！(you get up so early)、"hei shuai ge/gu niang"嘿，帅哥/姑娘(hey,boy/girl)