What will probably be the first stage of change as the sun becomes a r-考呗网

单选题What will probably be the first stage of change as the sun becomes a red giant?

[分析]细节题型
见第二段第二句并参照注释51：距今大约五十亿年后，太阳的核会缩小并且会变得更热，而太阳表面的温度会降低，然后太阳将会成为一个红色的巨星；因此D为答案。

1When the sun becomes a red giant, what will conditions be like on Earth?

2As a white dwarf, the sun will be____________________.

3According to the passage, which of the following best describes the sequence of stages that the sun will probably pass through?