An elderly couple goes to Burger King, where they carefully split
a burger and fries.
A trucker takes pity on them and offers to buy the wife her own meal.
"It's all right," says the husband. "We share everything."
A few minutes later, the trucker notices that the wife hasn't taken a bite.
"I really wouldn't mind buying your wife her own meal," he insists.
"She'll eat," the husband assures him. "We share everything."
The wife snaps
, "Because I'm waiting for the teeth!"
1. take pity on 怜悯，同情，例：take pity on the weak 怜惜弱者
convince sb. of sth. 例：The officials were eager to convince us of the safety of the nuclear reactors. 官员们急切想要让我们相信核反应堆是安全的。
b. 说服（某人做某事）= persuade
convince sb. to do sth. 例：I've been trying to convince Jean to come with me. 我一直在尝试说服Jean和我一起去。