In China, when greeting teachers or older individuals, it's customary to use more formal language and show respect. Instead of saying 'hi', you can say ', which literally means 'respectful salute'. When greeting a teacher, you can also use , which is a polite way to acknowledge their age and position. Another option is to say , which roughly translates to 'honored teacher' or 'venerable elder'. Remember to bow your head slightly when using these phrases to show respect and courtesy.