There _______ a football match tonight. [ ]
A. were
B. are
C. was
D. will be
答案:D
图纸上画出的某个零件的长是3.2cm,如果比例尺是1:20,则实际零件的长是_____ cm。
发电机的轴承绝缘垫中,需要夹一层铁垫,目的是为了保护绝缘垫的强度。()