Which is the most economical fuel for home heating-gas, electricity, or oil?

哪一种燃料用作家庭暖气最经济煤气、电力还是汽油？

youdao

Which is the most economical fuel for home heating-gas, electricity, or oil?

哪一种燃料用作家庭暖气最经济煤气、电力还是汽油？

youdao