These books use simple, hand-drawn pictures of "sad faces" and "happy faces" to illustrate ways people can prevent AIDS. (Para.9)
Meaning: Simple pictures of "sad faces" and "happy faces", drawn by hand, are used in these books to show how people can prevent AIDS.
illustrate: vt. add pictures to (sth. written); show the meaning of (sth.) by giving pictures or examples
The case illustrates that women can do much better than men in some fields. 這個事例說明了婦女在某些領域可以比男性干得出色得多。
Let me give another example to illustrate this difficult point. 我再舉個例子說明這個難點。