阅读下面短文，从短文后各题所给的A、B、C和D四个选项中，选出可以填入空白处的最佳选项。
My class and I visited Chris Care Center in Phoenix, Arizona to comfort the old people who needed a little cheering up during the holiday season.
The first two 1 there were for persons requiring help in taking care of themselves. We sang 2 for them. They loved our sweet songs and the flowers that we left with them.
As we were 3 on the third floor for old people with Alzheimer (老年痴呆症), most of them 4 off at the walls or floor. However, one lady 5 my eye. She was sitting by the door, in a wheelchair, singing songs to herself. They weren't the songs that we were singing, at least they didn't 6 like that. As we got 7 with each festive song, she did as well. The louder we got, the louder she got. 8 she was singing, she was also 9out to us with her hands and body. I knew that I should have gone over to her, but I thought that my 10 were to my students. People who worked at this center could 11 her, I thought. Just when I stopped feeling 12 about not giving her the attention she needed, one of my students, Justin, showed me what the holiday season is really about.
Justin also 13 the same lady. The difference between us is that he 14 on her needs, but I didn't. During the last song, "Silent Night," Justin walked over to her and held her hand. He looked this aged lady in her 15 and with his actions said, "You are important, and I will take my 16 to let you know that."
This tired, elderly lady stopped singing and held his hand. Then she touched his cheek with the other hand. Tears began to fall down her face. No 17 can completely describe that touching moment.
It 18 a boy to teach me, a man, about kindness and love. Justin's example of a complete, selfless attitude 19 another was a lesson that I will never forget. He was the teacher that day, and I consider myself 20 to have witnessed his lesson.
