What are the disadvantages of fuel cells?

题目

What are the disadvantages of fuel cells?
麻烦大家用英文回答一下吧..感谢ing.

答案

When they are used on vehicles:
1.shorter life compared with engines running on gas
2.could take a long time to recharge if they run flat
3.lower mileage at the present stage of development
4.expensive to manufacture
5.Disposal could be a problem (Current fuel cells are not harmless in terms of disposal/toxic substance/costly to dispose of)
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