The nurse would teach the client to implement which of the following nasal care measures after the nasal packing is removed

A．Irrigate the nares with normal saline solution daily.

B．Remove old blood from inside the nares with cotton-tipped applicators.

C．Avoid cleaning the nares for at least 2 days.

D．For comfort lubricate the membranes with a water-soluble lubricant.

计算题：已知石灰石含CaO52.5%，SiO21%，R=1.75，求有效CaO含量。