我市农民常在早春播种棉花后用地膜进行覆盖，目的是（　　）

A．防止害虫咬坏种子

B．保温保湿，利于种子萌发

C．防止种子霉变腐烂

D．隔绝空气，闷死杂草种子

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

A. make use of  

B. deal with

C. come up with  

D. go through