油品罐的安全附件主要有( )、阻火器、放水阀、排污阀。
A.安全阀
B.呼吸阀
C.泄压阀
D.报警器
参考答案:A
解析: 油品罐的安全附件主要有安全阀、阻火器、放水阀、排污阀。
按概算法分类,建设投资有哪几部分构成?
Mrs. Weng came back from France in 2010. She _________ there for four years.
A. works B. worked C. has worked