Some of the most significant hidden costs of fossil fuels are from the air emissions that ___ when they are burned.
A: weaken
B: occur
C: vary
D: impose
A: weaken
B: occur
C: vary
D: impose
举一反三
- U3T104. Known as externalities, the hidden costs of fossil fuels aren't ______ in their market price,
- When we burn fossil fuels, we put lots of carbon dioxide into the air and this is a ______ of Global Warming.
- This passage is primarily concerned with _____. A: the greenhouse effect B: the burning of fossil fuels C: the potential effect of air pollution D: the likelihood of a new ice age
- People are beginning to use clean energy sources mainly because _______. A: fossil fuels have caused a lot of pollution B: clean energy is cheap C: fossil fuels have cost a lot of lives D: they do not have enough fossil fuels now
- Air freight can accommodate heavy freight, and most companies do not impose ______ limits.