________by many wellknown experts and film stars，the product was very popular at one time.
A：To advocate
B：Having advocated
C：Advocating
D：Advocated
郑玄利用一切可以利用的机会刻苦学习，拜访各地名师，虚心向他们请教。郑玄主要学习、弘扬（ ）
下列关于概率的描述属于“等可能性事件”的是（ ）
