A. 对接焊缝 B. 角焊缝 C. 断续焊缝 D. 焊缝
A. 对 B. 错
A. Setting up lofty ideals. B. Loving the great motherland. C. Bearing the responsibility of the times. D. Having the courage to struggle. E. Developping excellent skills. F. Cultivating one's moral character.
A. 劳动说 B. 引入说 C. 影响说 D. 以上都是
A. 300 B. 200 C. 600 D. 500