Dangerous goods required to be “carried on deck only” should not be carried on closed vehicle decks,but may be carried on open vehicle deck when authorized by the competent authority concerned. ()
A. under deck
B. on deck
C. ondeck only
D. under deck only
在水泵设计中,为何单纯用增大叶轮外径的方法来提高叶轮所产生的扬程是不足取的?
How long warning must be provided by the CO2 warning Mann before CO2 is discharged into a space ().
A. 5 seconds
B. 10 seconds
C. 15 seconds
D. 20 second
发展商从国家通过各种途径取得土地使用权,用来开发房地产项目,()市场。
A. 一级市场
B. 二级市场
C. 三级市场