6. a. write the plural for each noun. 1. gas 2. bath 3. waltz 4. penny 5. roof 6. grapefruit 7. schoolchild 8. deer 9. sheep 10. woman. b. write the singular for each noun. 1. wives 2. men 3. teeth 4. mice 5. days 6. watches 7. armies 8 fish 9. swine 10. oxen