A virtual rise in the center of gravity may be caused by().
A. filling a partially filled tank
B. using an on board crane to lift a freely swinging heavy object
C. emptying a partially filled tank
D. transferring ballast from the forepeak to the after peak
查看答案
预应力筋的超张拉数值不得大于钢筋的屈服点。
A. 正确
B. 错误
何谓衬垫和隔票,它们的作用是什么?对于钢板、钢管、钢材怎么进行隔票?同港口不同包装物的隔票方法是什么?