【问】 “How can I help you the most?”

“____out of the way.”

A. For you to stay B. To stay C. By staying D. With your staying. (TOEFL，71.3，73.1)

答案为C。但我不理解by在此处的含义。

【答】 by+V-ing常常表示手段、方法或方式，可用来回答“how”的问题：

1. How did you finish the job so soon? ——By climbing on the roof. (LEG)

你用什么方法这么快就干完了?——我爬到屋顶上干的。

2. You can lock this window by moving this catch to the left.

你把窗钩向左拧，就能把窗户锁上。

3. They were making a living by selling souvenirs to the tourists. (EED)

他们靠向旅游者出售纪念品来谋生。

请做下面的英语试题：

He has a theory that it is possible to tell the time in day light by_______ into a cat's eyes.A. looking B. to look C. look D. looked