1. She learned to draw by tracing pictures out of old storybooks. 她通过描摹旧故事书上的图画来学绘画。
2. The public is urgently requested to assist police in tracing this man. 公众被紧急要求协助警方追踪这名男子。
3. The research effort has focused on tracing the effects of growing levels of five compounds. 研究集中跟踪5种化合物水平上升带来的影响。
4. You can see that only by tracing a particular family line, possibly back to the 14th century or beyond, will you discover which version of a surname is yours. 你可以看到只有通过追溯一个特定的家族谱系，可能追溯到14世纪或更早，你才能发现哪个版本的姓氏是你的。
