单项选择题
Deck beams on a ship are generally spaced at equal intervals and run（）.
A.longitudinally B.vertically C.transversely D.intermittently
单项选择题 Day-shapes must be displayed（）.
单项选择题 Daylight savings time is a form of zone time that adopts the time（）.
单项选择题 Dacron sails，when not in use，may be damaged if（）.
