账簿按用途不同可分为（）。
A.序时账簿
B.分类账簿
C.订本账簿
D.备查账簿
参考答案：A, B, D
At this moment the bell rang, ________ the end of class. [ ]
A. announced
B. having announced
C. announcing
D. to announce
船并连操纵系靠方法中，操纵船系靠保向船时，应顺风顶流。
