With an online course Lynn has over 300, 000 students all over China ____ her class through the Internet.         

A．attending

B．attended

C．attend

D．are attending

用焦油紫染色法，显示尼氏小体的颜色是（）

A.紫色

B.棕色

C.红色

D.蓝色

E.绿色