书证
参考答案：
是指以文字、符号或图案等表达的思想内容来证明案件事实的物品。
he will return to his native land.
A．It is long before that
B．It is before long that
C．It won’t be long before
D．It will be long before that
As a green hand, he doesn’t know______ it takes to start a business here.
A．when
B．how
C．what
D．which
