he had not hurt his leg, John would have won the race.
A. If
B. Since
C. Though
D. When
网友回答
(答案→)A. If
B. Since
C. Though
D. When
解析：if在此引出一个虚拟条件。又如：If he had asked me, I would have had to tell him the truth. 如果他问我，我就不得不告诉他真相了。If I had not got married, I would still have been living abroad, 如果我没结婚，我就会仍然住在国外。