(informal)the outcome of a situation is unpredictable
(非正式)世事难料
(N. Amer. informal)risk everything that one owns on a bet, investment, or enterprise
(北美，非正式)（在赌博、投资或风险事业上）孤注一掷；破釜沉舟
this isn't a great time to bet the farm on the Internet.
现在不是在因特网上孤注一掷的有利时机。
(informal)used to express doubt about an assertion or situation
(非正式)这拿不准
he may be a suitable companion—but don't bet on it.
他可能会是个合适的同伴——但这也难说。
(informal)used to express vigorous disagreement with a confident assertion
(非正式)敢打赌吗？（用于表示强烈不同意某种说法）
‘You can't be with me every moment.’ ‘Want to bet?’.
“你不可能时刻都和我在一起。"“打不打赌？"。
(informal)you may be sure; certainly
(非正式)你放心；当然，一定
‘Would you like this piece of pie?’ ‘You bet!’.
“你想吃这块馅饼吗？"“当然！"。
Of course; surely.
当然；的确