Dave went .his pockets looking for the keys.A for B to C across D through

题目

Dave went .his pockets looking for the keys.A for B to C across D through
为什么选D?理由?另外,为什么后面是looking 现在时?
期待高手的回答〜

答案

这里的through是副词,完全地,彻底地,符合句意.
Dave把口袋翻个底朝天来寻找钥匙.
looking在这里是动名词而不是现在分词,起的是名词的作用,表示“寻找”这一行为.
同样地,go shopping,go swimming 等等都是这种结构.
供参考.