It is estimated to be three times as common as uranium and all the thorium in the Earth's crust could have more potential energy than both uranium and the fossil fuel reserves combined.
(It; to be; ) (three times as common as uranium and all the thorium in the Earth's crust could have more potential energy than both uranium and the fossil fuel reserves; combined; )
It three times as common as uranium and all the thorium in the Earth's crust could have more potential energy than both uranium and the fossil fuel reserves
to be combined