We didn't know you were in trouble at that time, otherwise we________ you a hand.[ ]

A. had given      

B. gave

C. would give  

D. would have given

建立并保持定期开展职业安全健康管理体系审核的方案和程序，以评价生产经营单位职业安全健康管理体系及其要素的实施能否恰当、充分、有效地保护员工的安全与健康，预防各类事故的发生。这是( )的目的。

A．监测

B．测量

C．审核

D．改进