piece of cake

1.The boy snatched a piece of cake and ate it hungrily.

男孩抢过一块饼便贪婪地吃起来。

2.After climbing mountains in the Swiss Alps, going up English hills is a piece of cake.

爬过了瑞士的尔卑斯山后,爬英国的小山简直是小菜一碟。