他时而是一只鸟，时而是一架飞机，不！他只是魔术先生。

It's a bird, it's a plane - no it's Mr Magic.

youdao

不过他们时而可以帮我点小忙，帮我递个工具，或用磁铁找到掉落下去的钉子。只是他们只能呆在地面上，捶打废木料。

They helped in small ways-handing me tools, picking up dropped nails with a magnetic sweeper-but they preferred to stay on the ground, hammering scrap wood into sailboats and slingshots.

youdao

由于你原本每年就需要作为被试参加一定数量的实验，所以这次只是多了两个小时而已。

As you are required to act as an experimental subject for a certain number of hours in a year - this will be two more of them out of the way.

youdao