题目选项分析

Alternative energy sources, such as solar energy and wind farms, both of which could supply easily all of the US's energy needs, although they are more expensive to set up than fossil fuel power, they would provide vast savings over time, not only in direct upkeep, but also in medical costs due to lower cancer rates.

Although alternative energy sources, such as solar energy and wind farms, both of which easily could supply all of the US's energy needs, are more expensive to set up than fossil fuel power, they would provide vast savings over time, not only in direct upkeep, but also in medical costs due to lower cancer rates.