问题补充：
We’ll have to finish it , .
A. however it takes long
B. however long it takes
C. no matter how it takes
D. no matter how long does it take
答案：
A. however it takes long
(答案→)B. however long it takes
C. no matter how it takes
D. no matter how long does it take
解析：状语从句考查题。However连接状语从句时其后紧接形容词或副词，而且从句要用陈述语气。无论需要多长时间我们必须完成它。 选B
