FEDEX: https://www.fedex.com/zh-cn/shipping/surcharges.html
UPS: https://www.ups.com/cn/zh/support/shipping-support/shipping-costs-rates/fuel-surcharges.page
DHL: https://www.5idhl.com/#/createExpress/FuelSurcharge
顺丰国际: https://www.sf-express.com/chn/sc/support-more/international_fuel_surcharge_introduction