sketching

例句：

1. 1. He is good at sketching portraits of his friends.
   他擅长画朋友的肖像。
2. 2. During the vacation, she spent a lot of time sketching in her notebook.
   假期里，她花了很多时间在她的笔记本上画画。
3. 3. The artist created a detailed sketch of the building before starting the final painting.
   这位艺术家在开始最终绘画之前，先绘制了这座建筑物的详细草图。