Fossil fuels remain the largest source of energy for most countries.

化石燃料仍然是大多数国家最大的能源来源。

Aid groups say major shortages of fuel remain, limiting the transportation of supplies.

援助组织表示，燃料仍然严重短缺，限制了物资的运输。

But Russian fuel remains in high demand.

但俄罗斯燃料的需求量仍然很大。

About 880 tons of highly radioactive melted nuclear fuel remain inside the three reactors.

三座反应堆内仍有约880吨高放射性熔融核燃料。