在亚丁湾执行护航任务的我国海军军舰上，为防止海军战士出现皮肤粗糙、皮下血管出血现象，应常服

A．维生素A和维生素C

B．维生素A和维生素D

C．维生素A和维生素B

D．维生素C和维生素B

Nowadays, no single country can successfully________the global problems alone.[ ]

A. make use of  

B. deal with

C. come up with  

D. go through