主起重臂多为伸缩式，伸缩动作由伸缩油缸及同步伸缩机构完成的起重机是（ ）。

A．will always be lower when using LIFO rather than FIFO, during a period of rising prices
B．is the number of units of inventory sold multiplied by cost per unit of inventory.
C．is the number of units of inventory purchased multiplied by cost per unit of inventory.
D．will be the same amount when using LIFO or FIFO, during a period of rising prices.

A.急性肾小球肾炎
B.急进性肾小球肾炎
C.IgA肾病
D.肾病综合症