单选题   It is necessary that something urgent ______ to combat smuggling.
 
【正确答案】 B
【答案解析】考查虚拟语气。在“It+be+a.+that从句”中，that引导的主语从句谓语动词常用“(should)+动词原形”。用于该句型的形容词有necessary, important, urgent, essential, imperative, appropriate, advisable, desirable等。