溺水后岸边抢救的第一步是()
A、对溺水者行心肺复苏术
B、将溺水者俯卧于斜坡上,头低脚高
C、立即倾出呼吸道积水
D、进行人工呼吸
E、清除咽鼻腔的泥沙
参考答案:C
牙源性角化囊肿易复发的组织学、生物学基础是()
A.囊壁薄易碎,手术难以完整摘除
B.主囊的囊壁内可含卫星囊或微小的子囊
C.囊肿的生长方式特殊,常沿抗性小的途径生长
D.穿破骨组织与软组织粘连,手术不易彻底
E.衬里上皮有异形性
There were already 4 people in the car but they managed to take John as well. It ______ a comfortable journey.
A.can’t be
B.wouldn’t be
C.mustn’t have been
D.couldn’t have been