Is every part of the sun equally hot? 太阳的各个部分都一样热吗？

　　No, they aren't. Some parts are colder than other parts. 不是的。有些地方比其他地方冷。

　　How do we know that fact? 我们是如何知道这个事实的呢？

　　Because we can see the evidence. 因为我们看到了证据。

　　When you look at the sun with dark glasses, you will find black spots on the sun. 你戴墨镜看太阳时，会看到太阳上有黑点。

　　These spots are called sunspots. 这些黑点就叫太阳黑子。

　　Why do the sunspots look black? 为什么太阳黑子看起来是黑色的？

　　Because their surroundings are too bright. 因为它们的周围太亮了。

　　If you look at the sunspot only, they will look very bright. 如果你只看太阳黑子的话，它们看起来非常亮。

　　But these sunspots are less bright than their surroundings, so they look dark. 但这些太阳黑子要比周围暗，所以看起来是黑的。

　　Who found sunspots first? 谁第一个发现了太阳黑子？

　　Chinese scientists found sunspots for the first time in 28 B.C. 中国科学家在公元前28年第一次发现了太阳黑子。