敏感问题, 一触即发的敏感事件 (来源：http://www.EnglishCN.com)
a central issue, concern or characteristic, especially one that motivates people to make a choice
the principal desire that a salesman needs to "hit" in order to make a sale
A psychological propensity for immediate or predictable response or reaction, as to a political issue or marketing tactic:
an issue that presses voters' hot buttons.
Something that is of great interest or is known to elicit immediate or predictable response or reaction:
a new product that is a hot button among young consumers.