开放性气胸典型临床表现是()
A.呼吸困难、发绀
B.胸部可见吸吮性伤口,随呼吸气体出入伤口发出嘶嘶声
C.伤侧的胸部叩诊呈鼓音
D.皮下气肿
E.纵隔移位
参考答案:B
— I think teenagers should _____ to get their ears pierced.
— I agree with you. [ ]
A. are allowed
B. not be allowed
C. not allowed
在普通混凝土中,水泥用量约占混凝土总量的多少()
A.5%~10%
B.10%~15%
C.20%~35%
D.30%~35%