口袋内有一些大小相同的红球，白球和黑球，从中任摸一球，摸出红球的概率是0.3，摸出黑球的概率是0.5，那么摸出白球的概率是       .

While in university,  we were offered a number of after school activities to________our social skills.[      ]

A. create  

B. grow

C. develop  

D. settle