单级单吸悬臂式离心泵属于（）。
A、DA型泵
B、SH型泵
C、BA型泵
D、都不是
参考答案：C
—Excuse me. Could you please tell me where I can get a dictionary?
—_____. There's a bookstore on Yi meng Road. [ ]
A. Sorry
B. Sure
C. Good idea
D. Thank you
施工现场最高设备上避雷针，保护范围应当按照（）度角计算。
A.45
B.30
C.60
D.75
