It is only when an NBA player has aged and been through many battles he learns an import

问题补充：

It is only when an NBA player has aged and been through many battles he learns an important lesson: there is no “I” in “team”.

A. after

B. before

C. what

D. that

答案：

A. after

B. before

C. what

(答案→)D. that

解析：句意：只有当一个NBA球员年长了，并且经历了许多战役，他才能明白重要的一课，那就是在球队中没有自我。通过分析句子结构，可知这个句子中包含一个强调句， 故选D。