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

教材应体现时代特点和现代意识，关注人类，关注自然。理解和尊重多样文化，有助于学生树立正确的（）、（）、（）。