下列现象中，物体质量将发生改变的是 [ ]
A、一铜块压成铜片
B、一铁块用人造卫星带入太空
C、一杯水结成冰
D、锈蚀的铁球被磨得非常亮
答案：D
Many citizens urged their government to take measures to _______ their carbon emission to reduce greenhouse effects.
A．cut off
B．cut up
C．cut out
D．cut down
外科化脓性感染最常见的致病菌为
A．葡萄球菌、克雷白杆菌B．大肠杆菌、类杆菌C．葡萄球菌、大肠杆菌D．链球菌、类杆菌E．变形杆菌、克雷白杆菌
