视网膜脱离和玻璃体内膜状机化物的超声鉴别点是 ["A.前者呈"V"形;后者呈不规则膜状,有分叉","B.前者膜状回声尖端与视乳头相连,位置同定;后者位置不定","C.眼球运动时,前者与眼球壁呈垂直运动;后者呈不规则运动","D.CDFI在前者可见血供;后者无血供","E.以上均是"]
计划工作的前提条件是指计划在实施过程中预期的() ["内部环境","外部环境","不可控因素","A和B"]
下列视网膜母细胞瘤超声表现最有特征性的是 ["A.肿瘤呈类圆形、半月形或不规则形的低回声团块","B.肿块内见钙化点或钙斑","C.肿块内血供丰富","D.肿块边缘不整","E.肿块内见液性暗区"]
正常成年人眼轴长为 ["A.18mm","B.20mm","C.22mm","D.24mm","E.26mm"]
新产品开发常用的预测方法是() ["外推法","因果法","直观法","计量模型预测法"]
盐的种类决定土壤的性质,若土壤中盐类以碳酸钠和碳酸氢钠为主时,此土壤称为()土。