The ornamental design for a knife, as shown and described.
FIG. 1 is a perspective view showing a top side, front edge, and left end of a knife in accordance with this invention.
FIG. 2 is a top view of the knife of FIG. 1 showing the top side thereof.
FIG. 3 is a bottom view of the knife of FIG. 1 showing a bottom side thereof.
FIG. 4 is a front edge view of the knife of FIG. 1 showing the front edge thereof, wherein the opposite edge view of the knife is a mirror image of FIG. 4 and therefore not shown; and,
FIG. 5 is a left end view of the knife of FIG. 1 showing the left end thereof, wherein the opposite view of the knife is a mirror image of FIG. 5 and therefore not shown.
The broken lines illustrate portions of the knife in which the design is embodied that form no part of the claimed design.