_______— does the history lesson start?

—At nine o'clock.　Let's go at once.

A.　What               　　B.　When               　C.　How

完形填空
Time is very important in our lives. But it never had any importance in my life until I 　1　 a watch from my father that made me responsible(有责任). It 　2　 me the importance of time in my life.
I got this gift on a grey-sky day. I had to go to the 　3　 at 9:00 a.m. to pick up（接）my uncle Ali and take him to my father’s house. However, I forgot it 　4　 I was playing with my friends. Later on that day, around 11:00 a.m., I 　5　 my uncle, but I was late for him. He had got out of the plane and 　6　 a taxi to my father’s house.
I　7　 my father’s house at 2:00 p.m. at the same day . My father looked at me angrily. I said “hi” to him and my 　8　 uncle. My father asked me to sit 　9　 him and handed me this watch which was a gift from 　10　. It weighed 8 oz（盎司）and all of it was made of silver（银）. Then he said, “Essa, did you have fun 　11　 your friends today? What you did was not very nice and you should be sorry for your 　12　.” I felt sorry and told my father that I wouldn’t do it again. Then he said, “This watch will be a reminder(提醒物) for you. I hope today you have learned something 　13　.”
I learned a lesson from my father: to respect(尊重) time and 　14　 be late. The watch is important to me, not because of its  15　, but because of the lesson that I learned from it.