Choose the right alternative.

Over the lip of the  littlelittel dell, on the side away from the hill, they felt, rather  thenthan saw, a shadow  risenrise, one shadow or more than one. They strained  theirthere eyes, and the shadows seemed to  grewgrow. Soon there could be no doubt:  threetree or four tall black figures were  standingstaying there on the slope, looking  downdawn on them. So black were they that they  seemedseem like black  holeswholes in the deep shade  behindbefore them. Frodo  foughtthought that he heard a faint hiss as of  venomousvenom breath and felt a thin  piercingprancing chill. Then the shapes slowly  advantageadvanced.