______ to somebody,a British person often shake hands.A) On being introduced B) On introducingC) When introducing D) While introducing

______ to somebody,a British person often shake hands.A) On being introduced B) On introducingC) When introducing D) While introducing
______ to somebody,a British person often shake hands.
A) On being introduced
B) On introducing
C) When introducing
D) While introducing

______ to somebody,a British person often shake hands.A) On being introduced B) On introducingC) When introducing D) While introducing
on doing sth.意思是“一……就……”当英国人被介绍给别人时,通常会握手.

on when while都可以 这句的关键是要用be introduced to sb. 所以A