There is a three - feet-high fence in front of the house.
结构分析如下：
isfence 主谓一致,正确
in front of 在.前面,正确（注意：in the front of是在.内部的前面,例：The teacher is in the front of the classroom. ）
错误之处：
three-feet-high 复合形容词前置修饰名词（fence）,需要+连字符,但是feet须改为单数形式foot
正确形式为：
There is a three-foot-high fence in front of the house.