力的单位是 _________ ，物理实验中常用 _________ 来测量力的大小．
N；弹簧测力计
No progress was made in the trade talk as neither side would accept the conditions of _____.
A．others
B．the other
C．either
D．another
医疗器械经营企业不得经营什么样产品？
