She was educated at Beijing University, _____ she went on to have her advanced study abroad. [ ]

A. after which

B. from which

C. from that

D. after that

近年来，沙尘暴频繁在我国北方发生，严重干扰和危害了人们正常的生活。沙尘暴形成的人为因素主要表现在 [ ]

A．人类盲目地开发森林和草原

B．北方地区降水量少，常年干旱

C．北方温度较低，植被生长缓慢

D．北方野生动植物种类较少