in search of 与in order to 与in order that区别

in order to 和 in order that 意思一样用法不同,都是“为了要 ...”、“以便于...”的意思.in order to 后面直接加动词短句,in order that（比较不常使用）后面则是加完整从句.换言之,in order 后面要嘛是接不定式（to+动词原型）,要嘛是由连词that引导的从句.
例如：
They must hurry in order to catch the flight.
We need to study hard in order that we can get a high score from the test.
in search of 和上面这两个风马牛不相及,无从区别用法.
意思是“为了搜寻、寻找...”、“为了探求...”
例如：They came to this desert in search of an ancient burial site which no one had seen before.