In other words, the concentration of at any time is given by the initial concentration, t minus the rate constant times time.

换句话说，任意时刻A物质的浓度等于初始浓度，减去常数乘以时间。

youdao

T: Well, any bank will cash it at our present traveler's check-buying rate, which we somewhat better than at hotels because of the service charge.

出纳员：任何银行都是按现时买入旅行支票的兑换率来兑现的。这个兑现率我们已经列在这里了。当然，因为手续费的差异，我们的兑换率比旅馆的稍高些。

youdao

T: Well, any bank will cash it at our present traveler's check-buying rate, which we somewhat better than at hotels because of the service charge.

出纳员：任何银行都是按现时买入旅行支票的兑换率来兑现的。这个兑现率我们已经列在这里了。当然，因为手续费的差异，我们的兑换率比旅馆的稍高些。

youdao