We claim the ornamental design for a sink, as shown and described.
FIG. 1 is a perspective view of an embodiment of the claimed design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a front plan view thereof;
FIG. 5 is a rear plan view thereof;
FIG. 6 is a left plan view thereof;
FIG. 7 is a right plan view thereof;
FIG. 8 is a cross-sectional view thereof, taken along line 8-8 in FIG. 2; and,
FIG. 9 is another cross-sectional view thereof, taken along line 9-9 in FIG. 2.
The ornamental design which is claimed is shown in solid lines in the drawings. The broken lines in the drawings are for purposes of illustrating unclaimed portions of the design. Broken lines formed by equal length dashes show unclaimed portions of the design. Broken lines formed of unequal length dashes (i.e., dash-dot) show boundaries between claimed and unclaimed portions of the design. Symbolic break lines having a jagged element show that no particular length of the portion is claimed, such lines and any portion of the article between such lines forming no part of the claimed design.