预制安装钢筋混凝土板桥常用（）安装。
A.起重机
B.扒杆
C.跨墩门架
D.单导梁
参考答案：A, B
若a=25，b=-3，那么a1999+b2002结果的末位数字是______．
All vessels（）size shall, whether in a fairway or not,observe the International Regulation for Preventing Collisions at Sea 1972.
A.in spite of
B.irrespective
C.in respect
D.in matter of
