to do作目的状语和后位定位的区别（另请举几个典型的例子）

A:后位定位
I have something to do (to do 作后位定语修饰something,和something 有逻辑上的动宾关系）
He was the first person to reach the top of the mountain。( to reach the top of the mountain作后位定语修饰the first person,和the first person 有逻辑上的主谓关系）
B。目的状语
I got up early to catch the first bus。这句中的to catch the first bus是目的状语,修饰谓语got up)
He went to the raileay station to meet his friend。这句中的to meet his friend 是目的状语修饰went)
如果不定式前面可以加in order 或者so as （为了,以便） ,那肯定是目的状语
不懂追问*^__^*
再问： 恩 讲得很明白 那这句中的 Contemporary housing design in China usually follows a preoccupied real estate formula to limit risk in the market。 ”to limit risk in the market“应该是目的状语吧？整句话应该怎么翻译？preoccupied real estate formula译成啥比较准确
再答： 预设的房地产规则 中国当代的住房设计通常遵循预设的房地产规则，以限制房地产市场的风险。