未知题型 What does the author imply by saying 'there has been a considerable change of attitude towards speech snobbery'(ParA.3)?A.People all speak English like BBC announcers.B.There is a great change of attitude about how English should be spoken.C.Some people still think their way of speaking is inferior.D.Most people don't believe their way of speaking is inferior.

单项选择题 寡糖是由3个以上10个以下单糖分子通过糖苷键构成的聚合糖。（ ）

单项选择题 采用线下模式的平台一般采取口碑营销和网络营销的方式进行用户发展。