_______money, the boy had to give up school to support his poor family. [ ]

A. Lacked

B. Lacking of

C. Lacking

D. Lacked of

理想根管消毒药应具备的条件不包括（）

A.杀菌力强

B.性能稳定

C.渗透性不能强

D.不使牙齿染色

E.不刺激根尖周组织