木屋架下弦的轴线就是木料的中心线。( )
参考答案：错
You are to return the book to the library in two weeks.[ ]
A. supposed
B. want
C. shouted
D. thought
通风机的传动装置外露部分应有护罩，通风机的进气口或进气管路直通大气时应加装保护网或其他安全设施。( )
