______ for the timely investment from the general public, our company would not be so thriving as it is.A. Had it not beenB. Were it notC. Be it notD. Should it not be

步骤 1：理解句子结构
句子的主干是“our company would not be so thriving as it is”，表示“我们的公司不会像现在这样繁荣”。这是一个对过去事实的虚拟语气，因为“our company would not be so thriving as it is”是对现在情况的假设，而“for the timely investment from the general public”是导致这个假设的原因。

步骤 2：分析虚拟语气的结构
虚拟语气的结构是“Had it not been for...，our company would not be so thriving as it is”。其中，“Had it not been for...”是虚拟语气的条件句，表示“如果不是因为...”，而“our company would not be so thriving as it is”是主句，表示“我们的公司不会像现在这样繁荣”。

步骤 3：选择正确的选项
根据虚拟语气的结构，选项A“Had it not been”是正确的。选项B“Were it not”和选项D“Should it not be”都是对将来事情的虚拟，不符合句子的语境。选项C“Be it not”是错误的，因为它不符合虚拟语气的结构。