题目

The spaceship __________ to the space station. It brought back two astronauts.   A. has gone              B. have been                 C. has been                   D. have gone 答案：C现有六种物品：金属小刀片、塑料直尺、2B铅笔芯、食盐水、眼镜片、橡皮，小明将它们分成两类，如下表所示， 他是按照物质的哪种属性进行分类的  [     ]A，状态  B．颜色  C．硬度  D．导电性