下列疾病哪些可引起睑球粘连（）

A.重症沙眼

B.结膜天疱疮

C.Stevens-Johnson综合征

D.白喉

E.碱烧伤

---___________ English classes do you have every week?

--- Five.

A．How often

B．How long

C．How much

D．How many