The CCTV Spring Festival Gala is a big stage,____many new actors or actresses are tobecome famous [ ]

Do you often see Mr. Smith ______ on the playground —No! But he is often seen ______ Chinese Kungfu in the park.

下列各句中加横线的成语使用恰当的一项是（ ）

_________ we do, we must be _________.

Not until I began to work ____ how muchtime I had wasted