C.five metres long;five-metre-long
啥也不说了,比较一下下面的句子
The wall is five metres long.
The boy is five years old.
It is a five -metre-long wall.
He is a five- year-old boy.why比较一下就明白了：The wall is five metres long.The boy is five yearsold.It is a five -metre-long wall.He is a five- year-old boy