---Why do you come back so late?

---Because there were too many people in the supermarket, and I had to _____to pay for the things.

A．wait in line

B．cut in line

C．stand up

D．speak loudly

己识别的源于工作场所外，能够对工作场所内组织控制下的人员的健康安全产生不利影响的危险源：（）.

A、企业厂区边界的油罐

B、由厂区外输入至厂区内的天然气

C、承包方的运输车辆

D、邻近企业的一个大型氯气储罐