由器质性病变导致的长期开口困难称为（）
A.癔病性牙关紧闭
B.咀嚼肌群痉挛
C.颞下颌关节强直
D.破伤风后牙关紧闭
E.关节盘移位
参考答案：C
矿井火灾不会产生大量的有毒有害气体。
Before wore is commenced（）the officer responsible should ensure that power is shut off and warning notices posted on the bridge and in the machinery spaces.
A.near the ship’s whistle
B.on the funnel
C.in the vicinity of radio aerials
D.near the radar scanner
