前：front ；后：behind；
front：n.正面；前面；正前方；前部；
behind：prep.在(或向)…的后面;在(或向)…的背面；
n.义同bottom，委婉说法，即屁股
'There you are,' said a voice behind me.
“你来啦。”我身后一个声音说道。
He wasn't well, so we had to leave him behind.
他身体不适，因此我们只好把他留下。
There's a garden at the front of the house.
房子的前面有一座花园。
温馨提示：
