睾丸的主要功能是（ ）
A．只产生精子
B．只分泌雄性激素
C．储存精子
D．产生精子和分泌雄性激素
答案：D
This morning Jack came to school _______ than _______ student in his class. [ ]
A. much late; any
B. much later; other
C. much later; any
D. much later; any other
留鸟
