The sun was already up when they set off.

　　他們出發時太陽已經升起了。

　　I could feel the warm sun on my back.

　　我背上感受到了陽光的溫暖。

　　The earth takes a year to make a circuit of the sun.

　　地球繞太陽運行一周需要一年的時間。

　　The trees form a natural protection from the sun's rays.

　　樹木起天然的保護作用，遮擋了陽光的照射。

　　Our son's having problems with his reading and writing.

　　我們兒子在讀寫方面有困難。

　　Well, son, how can I help you?

　　那么，孩子，我能為你做點什么？