A-A+
A．They have difficulty identifying these cells
问题详情
A．They have difficulty identifying these cells.
B．They aren"t sure how these cells work.
C．They"ve learned how to reproduce these cells.
D．They"ve found similar cells in other species.
参考答案
正确答案：B
解析：What does the professor say about scientists who study the specialized cells in human bones?
