Sometimes he did not even keep a copy of his book.

有时他甚至不保留自己的作品。

You might want to keep a copy of the periodic table in your notebook.

您可能想在笔记本中保留一份元素周期表。

Thomas Jefferson kept a copy of Seneca beside his bed.

托马斯·杰斐逊在床边放了一份塞内卡的复制件。

I’ll keep a copy of the contract, and give you the original.

【original】我将留一份合同副本，把原件给你。

This is why I like keeping a copy of the original grid in the background.

这就是为什么我喜欢在后台保留原始网格的副本。

I also sometimes like to keep a copy of the grid in the background, just to help keep track of where everything ends up relative to where it starts.

我有时也喜欢在后台保留网格的副本 只是为了帮助跟踪每件事情的结束位置和开始位置。