老底: sb.'s past; sb.'s unsavory background 短语和例子揭老底 dig up sb.'s unsavory past; drag the skeleton out of sb.'s closet
揭开老底: dredge up some embarrassing facts about sb.'s past
揭人老底: dig up sb.'s old stories in order to discredit him; disclose sb.'s villainous life; expose a person's fault; reveal sb.'s past; reveal to the world sb.'s evil character; show sb. up
