题目

下列说法中正确的是(下述n代表任意正整数) (    ) A.在n s时就是指n s末时B.在n s时就是指n s初时C.在n s时就是从(n-1) s末到n s末这1 s时间D.第n s就是从(n-1) s末到n s末这1 s时间 答案：AD解析：由时间和时刻的概念可知AD正确.( C )2. When you come this afternoon，don’t forget to _my    book    here.    ( B ) Jim,please _ these    books    to  your mother.     (D )—Oh,I left my bag in the meeting  room. Would you help_it    for    me?           —Sure. Just wait here.       (A ) The box is too heavy . Please help me _ it.        A. carry    B. take        C. bring    D. fetch