单选题 Upon arrival in the city they were shocked to learn that all surviving hospitals were still being ______by crowds of casualties needing treatment.
A. enclosed B. embarrassed C. besieged D. penetrated

【正确答案】 C

【答案解析】[解析] 本题空格处是说所有幸存下来的医院依旧被成群需要治疗的伤员团团围住。四个选项中，A项enclosed的意思是“放入封套，装入，围绕”；B项embmTassed的意思是“使困窘，使局促不安，阻碍，麻烦”；C项besieged的意思是“围困，围攻，包围”；D项penetrated 的意思是“穿透，渗透，看穿，洞察”。根据题意，C项为正确答案。