形容词*后面的介词:in of的区别?

问题描述:

形容词*后面的介词:in of的区别?
Zhang Hua is the tallest of the three.
He works (the) hardest in his class.
请教在什么情况下用 in,什么情况下用 of .

of + 同类人或者事物之间的比较
in + 地点/ 时间范围
例如:
Mary is the tallest of all the girls in the class
Mary 与all the girls是同类比较
in the class 强调地点这个范围