When you have borrowed a book from the library you should keep it well as if it were of

问题补充：

When you have borrowed a book from the library, you should keep it well, as if it were of .

A. that, yours

B. one, yours

C. that, you

D. one, you

答案：

A. that, yours

(答案→)B. one, yours

C. that, you

D. one, you

解析：原句的意思是：当你从图书馆借到一本书时，你应该好好保管它，好像它是你自己的一本书。代词one指的是与前面提到的同名的东西（书），但不是那个东西，而that指的就是前面提到的东西。Yours代指“你的书”，one of yours“你的书当中的一本”。根据句意,可知选B.