预应力原材料必须保持清洁,避免损伤、锈蚀。预应力钢筋和金属管道在室外存放时,时间不宜超过( )。
A.2个月
B.4个月
C.6个月
D.10个月
参考答案:C
Please these things to your brother.He is at school [ ]
A.bring
B.look
C.take
孕妇,27岁,孕1产0,38周妊娠,规律性腹痛3小时,入院。胎方位为单臀位,估计胎儿重3000g,骨盆外测量正常
臀位最易发生并发症是:()
A.胎儿窘迫
B.产后出血
C.产褥感染
D.胎膜早破,脐带脱垂
E.胎足脱出