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. 这个事例说明了妇女在某些领域可以比男性干得出色得多。
Let me give another example to illustrate this difficult point. 我再举个例子说明这个难点。