这里是要选择[ for ] 大概解作“为了”,但是具体意思是要自己体会.
例子: It is for you.给你的.
-I bought a shirt for you.我为你买了一件衣服.
-I bought a shirt to you.我给你买了件衣服.
通常都是for + something/somebody ,to + do something/somebody
所以,问题里面:
It's time for lunch.
又或许相同意思的另一种说法:
It's time to eat lunch.
或许说的不是很好,希望你能够明白喇(;