Consider the following statements regarding streamline(s):
(i) It is a continuous line such that the tangent at any point on it shows the velocity vector at that point
(ii) There is no flow across streamlines
(iii)

		dx	=	dy	=	dz	is the differential equation of a streamline, where u, v and w are velocities in directions x, y and z, respectively
		u		v		w

(iv) In an unsteady flow, the path of a particle is a streamline
Which one of the following combinations of the statements is true?