单项选择题 ( )是意识形态工作的主战场、最前沿。A. 电视B. 广播C. 报刊D. 互联网
单项选择题 关系型数据库是由众多二维表(基表)构成的,基表的列(字段)是基表的数据结构,一般情况下是固定不变的。
单项选择题 Fill in the blank with the most appropriate choice. The experimental investigation __________ that the addition of these fibers reduces the thermal conductivity of the composite specimen and yield a lightweight.