重点讲解：
1. a piece of
（断下、撕下或切下的）块，片，段，截；
eg. I was hurt by a piece of falling masonry.
我被掉下来的一块建筑用石块砸伤。
eg. The teacher gave each of us a piece of filter paper before doing the experiment.
做试验前，老师给我们每个人发了一张滤纸。
eg. The baby was given a piece of candy.
这孩子拿到了一块糖。
2. stay away from
不去，远离；
eg. Government employees and officers also stayed away from work during the strike.
政府雇员和官员在罢工期间也没去上班。
eg. he doctor told him to stay away from such foods and drinks.
医生叫他不要吃这样的酒菜。
eg. Children must be warned to stay away from main roads.
必须警告孩子们远离交通要道。
