it was not until the accident happened ______

问题描述:

it was not until the accident happened ______
怎么选that i became aware of my follishness that为什么不能用when 3Q

这儿 that 是强调句型 It is/was ...+(强调部分)+ that+ 其他.
本句是强调的until the accident happened ,然后把主句中的not 前置.
意思是“直到事故发生时我才意识到我的愚蠢.”