—I know nothing about the history of the telephone. Could you tell me        ?   

— Yes, in 1876

A．who invented the telephone

B．how the telephone was invented

C．when was the telephone invented

D．when the telephone was invented

用（）策略的企业商品一上市便高价厚利。

A.薄利多销定价

B.高额定价

C.关系定价

D.渗透定价