NO.PZ2020020601000006
问题如下：
What does buying on margin mean?
解释：
Buying on margin means borrowing part of the funds necessary to buy an asset. The asset is held as collateral. If its value declines sufficiently far, the borrower will have to either provide further funds or be closed out.
老师能告诉一下这个知识点在哪里嘛，没点印象
