When does school begin?

W: Gosh, it’ s seven o’ clock now. I’ 11 be late for school again.
M: Don’t worry.  We still have fifteen minutes.  I’ll drive you there.

M: What are those shirts made of?
W: They are made of cotton, but sometimes made of wool or nylon.
M: Are those made of cotton more expensive?
W: Yes, that’ s right.