单项选择题 为避免桥梁墩台施工中出现冷缝，应保证在上层混凝土振捣时，下层混凝土(    )。 A. 已初凝 B. 未初凝 C. 无任何要求 D. 以上答案都不对

单项选择题 Our experienced staff members ( ) to match your business needs with the right price of equipment. A、trained B、training C、were trained D、train

单项选择题 以下程序的输出结果是：a = [“a”,“b”,“c”]b = a[::-1] print(b) A. [‘a’, ‘b’, ‘c’] B.  ‘c’, ‘b’, ‘a’ C.  ‘a’, ‘b’, ‘c’ D. [‘c’, ‘b’, ‘a’]