川贝母中炉贝的鳞茎呈长圆锥形状似马牙，故称（）
A.马牙贝
B.元宝贝
C.云头
D.云纹
E.五花层
参考答案：A
It was very late, but the teachers were ________ working hard in the office.
A．almost
B．already
C．still
D．ever
蓝氏贾弟鞭毛虫是________虫，姜片虫是________虫。
