useful adj. 1.有用的,有益的,有效的,有帮助的。 2.〔俚语〕值得称赞的,精通…的 (at)。 make oneself generally useful 事事有用,事事帮得来忙 (He must make himself generally useful. 他可事事都干得来)。 a pretty useful performance 相当精采的演出。 His wife is very useful at cooking. 他的妻子很会做菜。 adv. -ly ,-ness n.
species n. 〔sing., pl.〕 1.种类;【生物学】(物)种。 2.【逻辑学】种。 3.【原子能】核素。 4.【法律】形式。 5.【宗教】圣餐物。 a species of folly 一种愚蠢行为。 the four species 【数学】四则,加减乘除。 The Origin of S- 《物种起源》〔Darwin 的名著〕。 the [our] species 人类。
Some useful species for biological control were introduced in detail 本文还对一些在生物防治上有利用价值的种类作了重点介绍。
For the first time a remote mountainside location will be the centre of top-level planning on issues such as the reintroduction of plants to their natural habitats and the development of sustainable production systems for medicinal and other useful species 该计划将涉及包括将植物从新引进到其自然生长地,以及开发药用物种和其它物种的可持续生产系统等方面的问题。