问题
选择题
With online course Crazy English has over 20 million students all over China _______ the class through the Internet .
A．attend
B．attended
C．attending
D．to be attending
答案
C
本题考查have sb do/doing；have sth done的用法区别。have sb do 让某人做某事，have sb doing，让某人处于某种状态，have sth done让别人做某事。故选C。