let them loose,loose是形容词还是副词

问题描述:

let them loose,loose是形容词还是副词
let them loose,loose是形容词还是副词.By infecting animals and letting them loose in burrows...替换letting(a) allowing (b) leaving (c) introducing (d) turning ,为什么选d不选a

题目就这样吗?应该 更详细的语境吧····个人觉得是动词啊,“让他们在洞穴中释放(散播)”,这个意思吧·····为什们选D不选A,let loose是固定搭配,释放的意思,turn loose也是固定搭配,也是释放的意思,懂了吗?
请采纳为满意答案哦····