不属于陶瓷材料的特点的选项是( )。
A．高温化学稳定性B．极好的耐腐蚀性C．超硬D．易裂缝
参考答案：D
They became friends again that day. Until then, they _______ to each other for nearly two years.
A．didn't speak
B．hadn't spoken
C．haven' t spoken
D．haven' t been speaking
女性，38岁，血象三系减少，行99Tcm-PHY骨髓显像如图，正确的描述是()
A．黄骨髓出现灶性增生
B．预后良好
C．提示慢性再障
D．提示急性白血病
E．以上都不是
