118. The world wildlife fund has declared that global warming, a phenomenon most scientsts agree to be caused by human begings in burning fossil fuels, will create havoc among migratory birds by altering the enviroment in ways harmful to their habitats.
c) a phenomenon that most scientists agree is caused by human beings's burning of fossil fuels
我想问的是,之前经常看到的这种所有格形式的动名词,都被算为 awkward而被直接排除,为什么这道题里正确选项没有否定 ‘human being's burning of fuels’的形式,反而说这种形式'economical than constructions with prepsitional phrase'? 恳请大牛解答!谢谢~