It was not until 1911, _______ the first vitamin was identified, _______ people realized the importance of it．

    A． when; which     B． when; that      C． that; which     D． that; that

______he came back ______the truth.

A．Not until; did he know                    B．It wasn’t until; did he know

C．Not until; had he known                  D．It wasn’t until that he had known

 It was not until she had arrived home _______ her appointment with the doctor.

A. when she remembered                         B. and she remembered

C. did she remember                                  D. that she remembered

One day, when I was in high school, I saw a kid named Kyle from my class walking home from school with all his books. I thought to myself, “  36 would anyone bring home all his books for the weekend? He must really be 37 .”

As I was walking, I saw several kids running toward him. They ran at him,   38 all his books out of his arms and he fell down in the dirt. His glasses went  39 and landed in the grass.

My  40 went out to him. So, I ran over to him.   41 I handed him his glasses, he looked at me and said, “Hey, thanks!”

I helped him pick up his books, and asked him where he lived. As it  42 , he lived near me. We talked all the way home. Over the next four years, Kyle and I became best friends.

Kyle was the  43 student of our class, one of those guys that really found  44 during high school. Therefore he had the honor to prepare a  45 speech. On the graduation day, I could see that he was  46 . So, I patted him on the back and said, “Hey, big guy, you’ll be  47 !” He looked at me and smiled.

He cleared his throat, and began. “Graduation is a time to  48 those who helped you make it through those  49 years. Your parents, your teachers…but mostly your friends. I am here to tell all of you that being a friend to someone is the best  50 you can give him.”

I just looked at my friend with  51 as he told the story of the first day we met. He had planned to  52 himself over the weekend and was carrying his books home. “Thankfully, nothing happened. My friend  53 me from doing the unspeakable(不能说出来的).”

Not until that moment did I realize that you should never underestimate(低估) the  54 of your actions. With one small gesture you can  55 a person’s life. For better or for worse.

_____________ bad-tempered at times, he is still respected by all the students.

A．In spite of         B．Even if            C．Not until          D．Despite