题干
— How do you like the regulations of our school?
— The regulations are strict with the students and they require that students _______ at least 90% of the lectures.
A：will attend
B：will take part in
C：should attend
D：should take part in
答案(点此获取答案解析）
C
，其中
表示不超过
的最大整数，如
，若
有三个不同的根，则实数
的取值范围是