有一读者问： 有这样一道选择题：
(1)The young man and young woman were sitting behind him. He was sitting_________them.
A. before B. in the front of
C. ahead of D. in front of
问应选哪一个？ 请把四个选项区别一下。
这里最好选in front of。和before相比，in front of表的距离较近，同时也比较平易。before表示位置时，多用在较正式的文体中（可参看编号42），如：
(2)The men appeared before the judge yesterday.
(3)Life opened out before him.
in the front of的意思是“在……的前部”，实例如：
(4)He is sitting in the front of the class. 他坐在班上的前排
ahead of常有“在……之先”的含义，如：
(5)He is running ahead of me.
