piece of cake

例句：

1. 1. She was so happy that she could have a piece of cake for dessert.
   她很高兴，可以吃一块蛋糕作为甜点。
2. 2.The children were having a bit of cake and milk before bedtime.
   孩子们在睡前吃了一些蛋糕和牛奶。
3. 3. I'm just craving a piece of cake to satisfy my sweet tooth.
   我只是想吃一块蛋糕来满足我的甜食欲望。