That’s all for the introduction to your arrangements these days. So now ______ there are any questions, I’d like to go ahead and start the first video.

A．if

B．unless

C．until

D．though

中风闭证的病机是（）

A.热入心包

B.热结胃肠

C.邪实内闭

D.热动肝风

E.痰湿内阻