综采工作面安装电气列车时，根据坡度方向，应用支稳列车（）
A.单体柱
B.圆木点柱
C. * * 柱
D.稳车装置
参考答案：C, D
By the year 1889, there were just 541 bison ________ in the whole of North America.
A．leaving alive
B．to leave alive
C．to be left alive
D．left alive
