相对阈限
参考答案：
指刚好能引起差异感受的刺激变化量。操作定义为有50％的实验次数能引起差别感觉的两个刺激强度之差。
脊髓损害中位置觉与振动觉缺失，病变位于（）
A.脊髓小脑束
B.脊髓丘脑束
C.网状脊髓束
D.皮质脊髓束
E.脊髓薄束、楔束
Your vessel is damaged and listing to port. There is a short rolling period around the angle of list. The portside freeboard is reduced to 1 foot. There is no trim and the weather is calm. You should FIRST（）.
A.press up a slack double bottom tank on the port side
B.fill an empty centerline double bottom tank
C.pump out a slack marine portable tank located on the portside amidships
D.jettison the anchors and anchor cables
