The ornamental design for a brush, as shown and described.
FIG. 1 is a front perspective view of a first embodiment of the invention.
FIG. 2 is a top plan view of FIG. 1.
FIG. 3 is a bottom plan view of FIG. 1.
FIG. 4 is a front elevation view of FIG. 1.
FIG. 5 is a rear elevation view of FIG. 1.
FIG. 6 is a left side elevation view of FIG. 1; and,
FIG. 7 is a right side elevation view of FIG. 1.
The dashed lines in FIGS. 1- 7 are for illustrative purposes only and form no part of the claimed design. The projecting dashed pole member, dashed bristles, dashed threads and dashed hole are for purposes of illustration only and form no part of the claimed ornamental invention.