LC-MS的灵敏性检测常采用的测试样品为()
A.八氟萘
B.利血平
C.六氯苯
D.醋酸
E.萘
参考答案:B
Stop ____now! Please listen to me. [ ]
A. talk
B. talks
C. talking
D. to talk
对于有突出危险煤层,应采取开采保护层或预抽煤层瓦斯等区域性防治突出措施。