Regular- kindness, darkness, happiness, loneliness, sadness, weakness, exactly, honestly, speedily, angrily, happily, friendly, especially, teacher, actor, liar, biologist, assistant
Challenge- mosquitoes, varieties, beliefs, grievances, schedules, echoes, thieves, journeys, halves, passersby, substances, orchestras, pharmacies, sergeants, tomatoes, boundaries, instruments, encyclopedia