问题补充：
--Excuse me, sir. Would you do me a favour?
---Of course. What is it?
---I if you could tell me how to fill out this form.
A. had wondered
B. was wondering
C. would wonder
D. did wonder
答案：
A. had wondered
(答案→)B. was wondering
C. would wonder
D. did wonder
解析：句意：打扰一下，先生。你能帮我个忙吗？当然，怎么了？我想知道是否你能告诉我如何来填写这张表格？I was wondering if…我想知道是否，用过去进行时的形式表示一种非常委婉的语气并且心情特别急切，习惯用法，故选B
