测量操场的长,应该用( )来做单位;测量北京到上海的距离,应该用( )来做单位。
米;千米
— Shall I tell Sally about it?
— No, you _______. I've told her already.
[ ]
A. shouldn't
B. must
C. needn't
D. can't
基础教育课程改革的核心理念是什么?简述新课程倡导的学生观。