题型:单项选择题 客船上为乘客使用的扶梯与甲板的夹角,应不大于(),踏步高度不大于225mm,扶梯两旁应装有牢固的扶手,梯身背后应有衬板,全部踏步板上应设有防滑装置。A.40B.50C.55D.60 查看答案
题型:选择题 The traffic on the main streets has a longer green signal than______ on the small ones.A.one B.thisC.thatD.it 查看答案