十万八千里: a distance of one hundred and eight thousand li; poles apart; very far away; wide of the mark; 离题十万八千里 miles away from the subject; completely off the point
离题: digress from the subject; stray from the point 短语和例子发言不要离题。 don't diverge in your speech.; please keep to the subject. 你猜得离题太远。 your guess is all abroad
离题万里: be remote from the subject; be too far afield; be too far from the subject [mark]; completely off the point; go adrift far from the subject; go wide of the mark; it hit a long way from the