One cannot make a silk purse out of a sow's ear.

例句：

1. 1.She loves to eat apples for breakfast every day.
   她喜欢每天早餐吃苹果。
2. 2.The apple tree is my favorite flowering plant.
   苹果树是我最喜欢的开花植物。
3. 3. Apples are a great source of fiber and vitamins.
   苹果是一种极好的纤维和维生素来源。