It wasn't for several years that i had the oppertunity of seeing him.为什么用that呢

It wasn't for several years that i had the oppertunity of seeing him.为什么用that呢

强调句型只能用that.
强调固定句型：
it is/was (not) …… that……………………
不管is/was (not)后面是单数还是复数,be动词始终是is/was,引导词一定是that

that引出定语从句