应用哪种药物有助于胎儿肺泡上皮覆盖和产生表面活性物质() ["胰岛素","肾上腺皮质激素","缩宫素","胰高糖素","肾上腺素"]
简述肿瘤的临床表现。
提示胎儿窘迫的重要指标是() ["胎动减少","羊水有胎粪污染","新生儿误吸","胎儿心率变化","胎儿头皮血pH降低"]
小样本随机抽样中较准确而且便于实行的方法是() ["单纯随机抽样","机械抽样","分层抽样","整群抽样","分层加整群"]
新生儿复苏时血用量约() ["5~10ml/kg","10~20ml/kg","20~30ml/kg","30~40ml/kg","40~50ml/kg"]
简述肿瘤的转移方式。