选择题：在站场信号平面布置图上，站场股道的编号，正线编为( )数字。A、 阿拉伯数字B、 罗马数字C、 单数

How much has the company ________________ this year?选择一项：A. brought down B. brou

如图所示圆轴.已知F=8kN,M=3kN.m,［σ］=100MPa,若用第三强度理论求轴的最小直径，则D≥（ ）mm。 A、 79.8B、 66.7C、 77.

已知n阶方阵A与B相似，P为可逆阵，则 一定是AP与BP的相似变换阵.

_________ time and labor, cartoonists generally draw the hands of their characte

I’d like to introduce you ______ James Stewart, the new manager of our departmen