B
句意：我们可以从这个故事中了解到什么？
A 亚当和陈不仅很酷，而且很友好。
B. Hyun意识到外表不能说明真相。
C. 约翰一开始不想和Hyun交朋友。
D. Hyun是一个很酷的孩子，篮球打得很好。
☞根据文章倒数第五段：
I knew that Adam and Chen were going to make fun of me in front of John 我知道亚当和陈会在约翰面前取笑我
以及倒数第三段亚当说的话：
"Mr Turner says you're a good basketball player, John," said Adam. "How would you like to play with us at lunch break? Hyun doesn't know anything about basketball."
“特纳先生说你篮球打得很好，约翰，”亚当说。“你愿意在午休时间和我们一起打球吗？ Hyun根本不懂篮球。” 可知，亚当和陈想让约翰加入他们而不跟Hyun玩，所以亚当和陈不友好。故选项A表述错误。
☞根据最后一段：
I remembered the saying we learnt in class about not judging a book by its cover. I completely misjudged John. 我记得我们在课上学过一句话——不要以貌取人。我完全看错了约翰。并结合全文可推知，作者意识到不能以貌取人，因为外表不能说明真相。故选项B正确。
☞根据文章第四段：John walked over to my desk and sat down beside me. He smiled at me. "Hello." he said in a confident voice. 约翰走到我的桌子旁，在我旁边坐下。他朝我笑了笑。“你好，”他自信地说。
通过约翰的表现可知，约翰一开始想和Hyun交朋友。故选项C表述错误。
☞根据倒数第三段最后一行：
Hyun doesn't know anything about basketball.
Hyun 根本不懂篮球。可知选项D表述错误。
综上所述，本题选B
