单选题They had great difficulty

问题补充：

单选题Theyhadgreatdifficulty____thepeople____inthefire.A.in rescue, trappingB.to rescue, trappedC.in rescuing, who trappingD.rescuing, trapped

答案：

D解析考查difficulty和过去分词做后置定语，固定短语have great ditticulty( in )doing sth意思“做某事有很大困难”，后面的trapped修饰前面的people意思“被困在火里的人”，根据意思，可知选D