Hard（ ）he tried, he was unable to meet the deadline for the term paper.
A、
although
B、
as
C、
if
D、
since
【正确答案】：B
【题目解析】：
此句hard在句首，连词在中间，说明是倒装，且是形容词／副词＋as＋主语＋谓语的形式，表转折，选B。句意：尽管他努力尝试，但未能赶上期末论文的最后期限。
Hard（ ）he tried, he was unable to meet the deadline for the term paper.
Hard（ ）he tried, he was unable to meet the deadline for the term paper.
although
as
if
since
此句hard在句首，连词在中间，说明是倒装，且是形容词／副词＋as＋主语＋谓语的形式，表转折，选B。句意：尽管他努力尝试，但未能赶上期末论文的最后期限。