滚弯机床包括哪几种？
参考答案：
包括滚板机和型钢滚弯机。
Mr. Green _____ to the manager now. You'd better call him later. [ ]
A. talk
B. talked
C. is talking
D. was talking
当操作温度大于（）时，高温硫化氢腐蚀就随着的温度的升高而增加。
A、150℃
B、240℃
C、255℃
D、288℃
