After I had pictured it over and over again in my mind, the big dayfinally arrived: my first day at senior high!
这是外研版新教程高中英语必学一第1单元中的句子。
以前从未见过 big day 的说法，难道不应该是 great day 吗？
英语可以说big day，也可以说great day，两者意思大致相同（“特殊日子”），其中的big, great 均表示important, significant 的意思。如：
They’re eagerly waiting for the bigday. 他们在翘首企盼这个重大的日子。
He is already getting in trim for thebig day. 他已经在为那个特殊日子调整状况了。
She’s already counting down to the bigday. 她已经在对这一重大日子倒计时了。
They have been getting everythingready for the big day. 他们一直在为特殊日子做筹备。
As the big day nears, I’m starting toget nervous. 伴随那个特殊日子的临近，我开始变得紧张起来。
原句大意：AfterI had pictured it over and over again in my mind, the big day finally arrived:my first day at senior high! 经过我的脑海一遍又一遍地描绘之后，这个特殊日子要紧终于到来了：我高中生活的第一天！