conduit

1. N-COUNT A conduit is a small tunnel, pipe, or channel through which water or electrical wires go. 導琯; 水琯

2. N-COUNT A conduit is a person or country that links two or more other people or countries. 渠道; 通道[oft N 'for/to' n]

Pakistan became a conduit for drugs produced in Afghanistan. 巴基斯坦成了阿富汗制造的毒品的販運通道。