In the west, people make _______ a rule to send Christmas present to their relatives and friends.

A．this

B．that

C．it

D．the following

关于应用硫酸镁治疗妊高征，可出现中毒现象，下列哪项错误

A．中毒现象首先为膝腱反射消失

B．呼吸每分钟不少于16次

C．尿量每小时不少于600ml

D．镁中毒时，立即静脉注射10％葡萄糖酸钙10ml

E．尿量每小时不少于25ml