a walk in the park
US /ə wɔk ɪn ðə pɑrk/
UK /ə wɔk ɪn ðə pɑrk/

1.
小菜一碟, 轻而易举
something that is very easy to do
:
•
Learning to ride a bike was a walk in the park for him.
学骑自行车对他来说是小菜一碟。
•
Don't worry, this exam will be a walk in the park.
别担心,这次考试会是小菜一碟。