隔舱人孔是为了操作人员进入隔舱检查有无渗漏而设置的，平时用人孔盖封死。
参考答案：对
The British Museum, I think, is ________________ during the summer break.
A．worth being visited
B．worthy of being visited
C．worthwhile to visit
D．worth while visting
连接三个刚片的铰结点，相当的约束个数为（）
A.2个
B.3个
C.4个
D.5个
