题型分类：文章总结题

题干分析：选择概括性的正确选项。

选项分析：

B 选项为第三段前半部分重要信息。the oldest stars, are formed from hydrogen and helium gases 对应文章第三段第一句和第二句。they shine until they exhaust their fusible material 对应文章第三段第三句。

D 选项为第三段后半部分重要信息。relatively young stars 出自第三段第五句 Some of this dust is eventually incorporated into newly formed Population I stars。mostly hydrogen and helium gas but also contain heavier elements 出自第六句 consist mostly of hydrogen and helium gas, hey also contain heavy elements。

F 选项为第五段重要信息。The outer envelope... will release their energy into space 对应第五段倒数第三句 gradually releasing the material of its outer envelope into space。become white dwarfs before they finally give off their last energy 对应倒数第一句和第二句。

A 选项 The Sun is a good example 对应文章第三段最后一句，但是前一句说的是 Population I stars contain material that once belonged to stars from previous generations，没有提 nuclear fusion rather than through contraction。

C 选项 Population II stars are found in the galactic disk 与第二段的最后一句话 Population I stars are found mainly in the galactic disk 矛盾。

E 选项对应文章第四、第五段。但是在第四段末提到 Then, at some point in the far future, all nuclear reactions in the Sun’s center will cease，然后第五段才开始描述太阳分为内部和外部的情况，所以说是核聚变停止在先，然后太阳才开始分为2个部分。选项时间顺序颠倒。