在“武德合金，氧气，熟石灰，一氧化碳，干冰，氧化钙 ”中选择适当的物质填空。（每种物质限选一次）

（1 ）可用于人工降雨的物质是_________ ；  

（2 ）制作保险丝的材料是_____________ ；

（3 ）可用于炼钢的气体是____________ ；  

（4 ）可用于改良酸性土壤的碱是________ 。

When caring for a client who has recently delivered, the nurse assesses the client for urinary retention with overflow. Which of the following provides the most accurate picture of retention with overflow

A．Frequent trips to the bathroom with an average output of 200 to 300 mL per void.

B．Intense urge to urinate with an average output of 250 mL.

C．A varying urge to urinate with an average output of 100 mL.

D．Uterus displaced to the right with increased vaginal bleeding.