第11题: [单项选择]An unstable upright equilibrium position on a vessel means that the metacenter is(). A. lower than the center of gravity B. at the same height as the center of gravity C. higher than the baseline D. on the longitudinal centerline 参考答案:A
A. over a century ago B. in the middle 1960s C. in the late 1980s D. in the year 1980 参考答案:C 答案解析:该题问:高效率的现代通讯系统是在什么时间开始的 A项意为“一个世纪之前”;B项意为“在二十世纪六十年代中期”;D项意为“1980年”,这三项都不正确。C项正确,因为在第五段的最后一句提到In 198