【单选题】多缸发动机各气缸的工作容积之和,称为( ) 。
【单选题】We last night, but we went to the concert instead.
【判断题】熔化极氩弧焊是以隋性气体氩气作为保护介质的一种焊接方法,它只适用于焊接薄的工件。
【简答题】2 A. We went to our first baseball . It was very slow. B. We went to our first baseball , it was very slow. C. We went to our first baseball , and it was very slow.