The first step to plugging these methane leaks is pinpointing them.

堵塞这些甲烷泄漏的第一步是确定它们的位置。

For several years now, the OECD, a club of rich countries, has convened governments in the hope of plugging the tax leaks.

几年来，富国俱乐部——经济合作与发展组织（OECD）召集各国政府，希望堵住税收漏洞。