问题
选择题
I am very grateful to my high school teachers, without _____ help I wouldn't be so excellent.[ ]
A. whom
B. them
C. which
D. whose
答案
答案：D
搜题请搜索小程序“爱下问搜题”
I am very grateful to my high school teachers, without _____ help I wouldn't be so excellent.[ ]
A. whom
B. them
C. which
D. whose
答案：D
，那么a1的取值范围是（）。
)