单项选择题
A.make them easier to understand B.provide more useful words C.introduce more contexts D.include more examples
A.The first Sunday of each month. B.Every day from 10 am to 3 pm. C.The first day of each month. D.Every weekend in winter.
A.It is small and cheap. B.It has a larger vocabulary. C.It has 40% more examples. D.It is designed for students and teachers.