患者从慢性支气管炎阶段发展成阻塞性肺气肿的过程中最先发生的病理改变是
A.肺泡膨胀
B.细支气管不完全阻塞
C.肺泡壁弹性减退
D.肺小动脉痉挛
E.肺纤维化
参考答案:B
Given the following inventory data about a firm: Beginning inventory 20 units at $ 50/unit Purchased 10 units at $45/unit Purchased 35 units at $ 55/unit Purchased 20 units at $ 65/unit Sold 60 units at $ 80/unit What is the inventory value at the end of the period using FIFO()
A. $3100.
B. $3475.
C. $1575.
与工程建设密切相关的岩石性质有岩石的密度、孔隙性、吸水性、软化性、抗冻性和透水性等。