问题
选择题
----How soon will you send the book to me?
----It will be two days _______ you receive my book.
A．before
B．that
C．since
D．when
答案
答案：A
考查连词。before 在什么之前，才，就，since自从，when 当什么时候，句意：你多久把书寄给我？再过两天你就会收到我的书。所以选A。