新生儿做血细胞计数,多用下列哪个部位采血()
A. 手背
B. 耳垂
C. 足跟两侧
D. 肘部静脉
血液的PH值正常参考范围是()
A. 7. 15-7. 25
B. 7. 25-7. 35
C. 7. 35-7. 45
D. 7. 45-7. 55
A steel structure workshop (without crane and internal mezzanine floor) is designed with a span of 30 m, and there is little difference between eaves height and mid-span height, so it is most suitable for use the ( ).
A. Pitched roof symmetric portal frame
B. Propped portal frame
C. Tied portal frame
D. Mono-pitch portal frame
E. Mansard portal frame
Which of the following structural members belongs to the primary steelwork of portal frame buildings. ( ) (There are more than one correct choice)
A. columns
B. rafters
C. side rails
D. purlins
E. wall cladding
F. roof cladding
G. bracing