压缩系数 的下标a1-2的含义是 ( )。 (1)1表示自重应力,2表示附加应力; (2)压应力从1MPa增加到2MPa (3)压应力从lOOkPa增加到200kPa; (4)无特定含义,仅是个符号而已 (7.5分) A. 1表示自重应力,2表示附加应力 B. 压应力从1MPa增加到2MPa C. 压应力从100kPa增加到200kPa D. 无特定含义,仅是个符号而已
【简答题】What do you think our life will be like in 2050? Some people are talking about it on QQ. Blue Sky I think there won’t be any TV channels (频道) in 2050. People will be able to choose (选择) a programme ...