青云翻译

As long as you promise to return, you can go through this book. (Promise to ... as long as ...)

As long as you promise to return, you will be able to borrow the book. （promise to... as long as... ）

So long as you comply to return, you may borrow this book.(promise to… as long as…)

As long as you promise to return them, you can put this book borrowed. (promise to ... as long as ... ).

As long as you promise to return, you will be able to borrow the book. （promise to... as long as... ）