What is the best word to fill in the gap ?
It now appears that far fewer trees have been cut down than (10)____ previously suspected to be the case , the reason(11) ___ that earlier estimates of tree numbers were inaccurate . moreover ,(12 ) ____ of the forest of west africa's part is neither as ancient nor as undisturbed as people thought
My answer : what , is , most
but my teacher says I'm wrong . WHY ?