Many contain other legal stimulants like taurine, guarana and L-carnitine.

许多含有其他合法兴奋剂，如牛磺酸、瓜拉纳和左旋肉碱。

But unlike soda, coffee and tea, energy drinks add in guarana extract.

但不像碳酸饮料，咖啡和茶，功能饮料加入的是瓜拉纳提取物。

But it also occurs in tea, chocolate, kola nuts, guarana seeds and even the flowers of citrus plants.

但它也存在于茶、巧克力、可乐果、瓜拉那种子，甚至是柑橘类植物的花朵中。

They sometimes include sugar, vitamins and guarana, another stimulant.

它们有时包括糖、维生素和瓜拉那，另一种兴奋剂。

The guarana plant which is native to South America produces seeds which are about the same size as a coffee bean, but yields twice the caffeine content.

瓜拉纳植物原产于南美洲。产生的种子和咖啡豆的大小差不多。但却有两倍的咖啡因含量。

These include two South African plants: yerba matte and guarana, the latter you probably have heard of as an additive in some energy drinks.

其中包括两种南非植物：巴拉圭茶和瓜拉那，您可能听说过后者作为某些能量饮料的添加剂。

A study in the " Journal of Pediatrics" found their most common ingredients include caffeine, a stimulant, guarana, a stimulant, ginseng, a root that's believed to be stimulating, and lots of sugar.

一篇刊登在“儿科杂志”上的研究发现这种饮料中通常会含有大量包括咖啡因、兴奋剂、瓜拉那、人参以及大量糖分在内的物质。