污水的高级处理中，常用A/O法进行生物脱磷，其机理为一些细菌在有氧时释放磷，而在无氧时吸收磷，对富磷污泥的分离即可实现脱磷。

AD Ltd manufactures and sells a single product, E, and ...

单项选择题AD Ltd manufactures and sells a single product, E, and uses a standard absorption costing system. Standard cost and selling price details for product E are as follows. $ per unit Variable cost 8 Fixed cost 2 10 Standard profit 5 Standard selling price 15 The sales volume variance reported for last period was $9,000 adverse. AD Ltd is considering using standard marginal costing as the basis for variance reporting in future. What would be the correct sales volume variance to be shown in a marginal costing operating statement for last period?
A、$6,428 (A)
B、$6,428 (F)
C、$12,600 (F)
D、$12,600 (A)

自然灾害、事故灾难和公共卫生事件的四级预警用（）标示。A.蓝色B. 黄色C. 橙色D. 红色

单项选择题自然灾害、事故灾难和公共卫生事件的四级预警用（）标示。

移动式压力容器（罐车、罐式集装箱等）因交通事故、气瓶因火灾引发特种设备爆炸、泄漏、损坏等，且非设备本体原因，这...

问答题移动式压力容器（罐车、罐式集装箱等）因交通事故、气瓶因火灾引发特种设备爆炸、泄漏、损坏等，且非设备本体原因，这些事故是否属于特种设备事故？我们应该做哪些工作？