Not until he went through real hardship _____the love we have for our families is important.

A．had he realized

B．did he realize

C．he realized

D．he had realized

以下哪项可以将劣质原材料引起的成品缺陷减少到最低限度

A．对恰当处理在产品库存采取文件备案。
B．要求对所有采购活动规定原材料规格。
C．及时跟踪所有不利使用差异。
D．在生产过程结束时确定损坏金额。