twos-thirds, two-thirds, wwos-third: othenwise, rather than, bes

twos-thirds, two-thirds, wwos-third: othenwise, rather than, besides
The satellite study shows that about____ of the sea-level rise caused by the Greenland ice sheet is due to icebergs breaking off from fast-moving glaciers____ simply the result of water running off from melting ice
【正确答案】:two-thirds; rather than