Undefined variable

undefined [,ʌndi'faind]

adj. 未阐明的;未限定的;

variable ['vɛrɪəbl]

adj. 变化的，可变的;[数]变量的;[生]变异的; n. 可变因素，变量;易变的东西;

vari=vary变化+able形容词后缀→易变的

Sorry, I've already got plans.

对不起， 我有事。

When would you like to leave?

你要什么时间离开呢？

The mammoth has now been restored in the Palaeontological Museum in Leningrad. Other animals were trapped in tar pits, like the elephants, sabre-toothed cats, and numerous other creatures that are found at Rancho la Brea,which is now just a suburb of Los

这头长毛象已被修复，现存于圣彼得堡古生物学博物馆。有的动物掉进天然沥清坑里被保存下来，如在兰桥。拉。布里 -- 现在是洛杉矶的郊区发现的大象、剑齿虎和许多其他动物。