单词	pyrethrin
释义	pyrethrin /pʌɪˈriːθrɪn / noun Chemistry Any of a group of insecticidal compounds present in pyrethrum flowers: pyrethrins can cause allergic reactions [mass noun]: it contains natural pyrethrin... Many of these sprays contain one or more of a group of insecticidal compounds known as pyrethrins. These synthetic chemicals mimic the action of natural pyrethrins derived from chrysanthemum flowers. Citrus-oil products, pyrethrin products, as well as those with pyrethrins and diatomaceous earth, may be effective. Origin 1920s: from pyrethrum + -in1.
随便看	have a foot in both camps have a frog in one's throat haveage have-a-go have a go at have a (good) run for one's money have a hand in something have a heart have a heart of gold have a lash at have all day have a lock on have a long way to go have a lot (or not much) on the ball have a mind of one's own have a moment have a mountain to climb have an axe to grind have an eye for have a nice day have ants in one's pants have a/one's cross to bear have a (or a good or half a) mind to do something have a (or one's) bellyful have a plum in one's mouth

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