A back may pertain-to a foot.Logical formLearned from200 sentences. A female may rub a back.Logical formLearned from200 sentences. A length may pertain-to a back.Logical formLearned from200 sentences. A (back pocket) may pertain-to jeans.Logical formLearned from199 sentences. A back may pertain-to necks.Logical formLearned from198 sentences. A back may pertain-to a screen.Logical formLearned from198 sentences. A back may pertain-to a left hand.Logical formLearned from197 sentences. A back may pertain-to a top.Logical formLearned from197 sentences. Persons may turn backs.Logical formLearned from196 sentences. A back may pertain-to an envelope.Logical formLearned from195 sentences. A back may pertain-to fingers.Logical formLearned from194 sentences. A back may pertain-to a device.Logical formLearned from194 sentences. A back may pertain-to a ship.Logical formLearned from193 sentences. A male can be a defensive back.Logical formLearned from193 sentences. A top may pertain-to a back.Logical formLearned from193 sentences.