托福阅读高难度文章长难句实例解析：未被发现的气体

　　Ramsay then studied a gas that was present in natural gas deposits and discovered that it was helium, an element whose presence in the Sun had been noted earlier in the spectrum of sunlight but that had not previously been known on Earth.

　　句子分析

　　本句主句有两个并列的谓语动词，分别是studied和discovered。本句被简化后的主要意思就是：Ramsay then studied a gas and discovered that it was helium。在前半句中，有that引导的定语从句，修饰前面的a gas。在后半句中，an element是helium的同位语，起到解释补充的作用。紧接着an element后面有两个定语从句，分别由whose和that引导，都是修饰前面的同位语an element。

　　单词回顾

　　gas deposits指的是“气体沉淀物”，deposit还可以作动词，除了表示“使沉积”以外，还可以表示“存入”，比如：You are advised to deposit your valuables in the hotel safe. 建议您把贵重物品存到旅馆的保险箱里。

　　helium表示“氦气”。

　　spectrum在本句中表示“光谱”的意思，它还可以指“(思想、观点等)范围”，比如：Our speakers tonight come from both ends of the political spectrum. 我们今晚的演讲人来自政坛的两个极端。

　　句子翻译

　　然后，拉姆齐研究了一种存在于自然气体沉淀物中的气体，并发现这种气体是氦气，氦元素在早期的太阳光谱中已经被发现过，但是之前在地球上从未找到过它。