She laid the book down on the table.

她把书放在桌上。

Put your book down on the desk.

请把你的书放在书桌上。

I could not put the book down!

我无法放下这本书！

When that happened, he put the book down.

一出现这种情况，他就会放下书本。

He marked the book down to 49 cents.

他把书的标价降低为49美分。