"我们吃个冰淇淋吧。" "好啊，为什么不呢？"

"Let's have an ice cream." "Yes, ___why ___not?"

当朋友邀请我去看电影时，我说：“为什么不呢？”

When my friend invited me to the cinema, I said, "___Why ___not?"

"我们可以去散散步。" "为什么不呢？天气真好。"

"We could go for a walk." "___Why ___not? It's a lovely day."