铁筒式风桥其质量标准为:() ["风桥应使用不燃材料构筑;","铁筒直径不小于750mm,壁厚不小于5mm;","设铁筒风桥巷道两侧各砌两道带风门的密闭隔墙,隔墙四周要掏槽;","风桥产生的通风阻力不得超过150pA.,风速要小于10m/s;","风桥的漏风率不大于2%"]
4G数据终端流量130元套餐包含() ["2G/3G/4G国内流量(不含港澳台)2G","省内单模数据流量(4G)1G","2G/3G/4G国内流量(不含港澳台)3G","省内单模数据流量(4G)2G"]
宫内节育器取出适应症。() ["计划妊娠或不必继续避孕者。","到期须更换或已闭经半年以上者",".要求改用其他避孕方法或绝育者","反复阴道炎治疗效果不佳"]
按材质分风筒有哪几类?() ["金属风筒","胶皮风筒","塑料风筒","木质风筒","布质风筒"]
IUD导致出血的因素。() ["Ⅷ因子于放置IUD后普遍降低","IUD引起子宫内膜无菌性炎症或异物反应,使前列腺素产生过多,而使血管扩张并抑制血小板聚集。","纤溶酶原激活剂水平增高和纤维蛋白原溶解活性增强啊,致内膜止血作用不正常","费溃疡区血管渗透性增加"]
先期完井和后期完井的区别是什么,各自有什么优点?