Task-based teaching method fits both language knowledge and skills. 
A、正确
B、错误

A．(X’ + Y’)·(X’ + Y) = X
B．X + Y·X + Y’ = X
C．(X + Y)·(X + Y’) = X
D．X’ + Y·X + Y = X’

A．六个
B．七个
C．五个
D．四个

A．对
B．错