— Who was on duty last Friday?
— . [ ]
A. I am
B. I was
C. Yes, I was
D. No, I wasn't
答案:B
光固化基托材料的光照固化深度一般范围是()
A.1~2mm
B.3~5mm
C.2~3mm
D.4~6mm
E.0.5~1.0mm
“一带一路”建设的重要支撑是()。
A、投资贸易合作
B、资金融通
C、政策沟通
D、基础设施互联互通