元朝四等人的阶级压迫肇始于：（）
A、元太祖
B、元世祖
C、元成宗
D、元英宗
参考答案：B
小麦叶肉细胞中的核酸，含有的碱基种类是[ ]
A．5种
B．4种
C．1种
D．8种
— Would you like something to drink?
— Yes, ____________. [ ]
A. I would like
B. I would like to
C. I would
D. I like
