I smell a rat.
First,you are insulted by a new poster after having posted an innocuous post.The insult being sth like "you are not the brightest bulb in the pack."
Second,you are naturally offended.So you ask that poster how long he's been in China?
Third,the initial insult is "replaced" by new wording asking what other FT'S think,and is no longer on the thread.
Finally,you are insulted by that poster again re your teaching prowess.
Pity I can't e-mail you,but you could e-mail me.I'd like that.Bill is no newbie,believe me!