根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
When I was 16 years old，a boy gave me an important gift． 1
It was the early autumn of my first year at a junior high school，and my old school was far away．2 I was very lonely，and afraid to make friends with anyone．
Every time I heard the other students talking and laughing，I felt my heart broken．I couldn’t talk with anyone about my problems．And I didn’t want my parents to worry about me．
Then one day，my classmates talked happily with their friends，but I sat at my desk unhappily as usual．
3 I didn’t know who he was．He passed me and then turned back．He looked at me，with a smile on his face．
Suddenly，I felt the touch of something bright and friendly．It made me feel happy，lively and warm．
4 I started to talk with other students and made friends．Day by day，I became closer to everyone in my class．The boy with the lucky smile has become my best friend now !
5 I believe that the world is what you think it is．If you think it lonely，you might always be alone．So smile at the world and it will smile back．
A．At that moment，a boy entered the classroom．
B．He’s living in Australia now and he loves it．
C．It doesn’t matter because all the dark days have gone．
D．It was a smile． E．That smile changed my life．
F．It’s practically impossible to make friends here．
G．As a result，no one knew who I was．