Who originally sings "if you don't know me by now"? it is under percy sledge, the ojays, michael bolten, marvin gaye, harold actually sang this? i know michael bolten did a remake, but i am looking for the original.

The region of the united states where beef and hog production is prevalent is the midwestthere are 12 states in this area including  illinois,  indiana,  iowa,  kansas,  michigan,  minnesota,  missouri,nebraska,  north dakota,  ohio,  south dakota, and  wisconsin. all of these states are known for their meat and such products. 

Iwould say d) signed unknown street singers who brought original songs to record.

What are the statements : ) ?