Fill blank (iv).

Directions: Read the following passage having some numbered blanks.

The Temiar blowpipe is normally some two metres long and made ______(i)______ one single length of bamboo. It has a slender inner tube ______(ii)______ the outer covering so that one length warps against the other and it always remains true. From it they shoot a small dart, a splinter of wood some twenty or twenty-five centimetres in length; a pith cone at one end, the other sharpened end tipped with poison. Most aborigines are ______(iii)______ accurate with a blowpipe up to a range of nine to ten metres, though ______(iv)______ some reason they are more accurate if the target is moving vertically than if it moves horizontally.