云冈石窟，开凿于_________，石窟内容丰富；龙门石窟，开凿于_________迁都洛阳之后，有洞窟和壁龛数千个。
北魏初年；北魏孝文帝
Good heavens! There you are! We _____ anxious about you, and we _____ you back throughout the night.
A．are； expect
B．were； had expected
C．have been；were expecting
D．are； were expecting
关于婴幼儿化脓性颌骨骨髓炎的病因，错误的是（）
A.脐带感染
B.人工喂养奶嘴创伤
C.中耳炎
D.局部皮肤疖肿
E.败血症
