— ______ is this shirt?
— It's ninety-nine yuan. ( )
A:How many
B:How much
C:How old
一条裙子原价75元,“五一”期间商城举行优惠活动,买了10条。妈妈用了多少钱?
下列关于“电子邮局”“网上会诊”“网上售货”的说法.不正确的是 ( )