阅读下面短文，从短文后各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项。
I live in a big city with a lot of homeless(无家可归的) people. Luckily there're small ways of helping them and you needn't have a lot of 1.
One way to help is to buy their monthly magazine. 2 doing this one day, I got to 3 a young homeless man, He was often 4 the magazine at the train station.
He was a poor farmer from another country. After a while, I found that his 5 was close to mine. It 6 that we were born in the same month.
I met him last year 7 after his birthday, and after congratulating him, without 8, I asked if he had had a good day. He 9 and said he hadn't really celebrated. I felt so 10.
I just couldn't think of this nice, young man being 11 on his 25th birthday with no presents, no cake, nothing! So I went home and looked in my yarn（纱线） basket. 12 for me, I had enough yarn 13. I set to work and knitted（编织） a 14 for the young man. The yarn had become a little dirty 15 I didn't knit very often. Then I washed the yarn so the scarf would be 16 when he got it.
I met him on my own birthday as I was going shopping. I had 17 to meet him so I had 18 the scarf and a piece of my own birthday 19 around with me. He was very happy with these gifts and so was I. The 20 in his eyes was the best present he could have given me!
”，tián），Ts的原子核外最外层电子数是7，下列说法不正确的是（ ）