joint variance的用法和樣例：
例句
- Even with necessities, differences in taste and patterns of consumption lead to variance in the price structure.
甚至就生活必需品而言，消費品的味和方式上的不同會(huì )導致價(jià)格結構上的差異。 - This may not be realistic since there with more education may experience larger variance in wages.
如果接受高等教育的人面臨的機會(huì )更多，收入的差異可能更大，在這一情形中，上述假定未必成立。
