Can someone help me?

Which behavior of an expectant mother is unhealthy

1. pass through the cochlea, are transformed into nerve impulses and sent to the brain hair cells 2. forms in your outer ear and is meant to protect your ear from dirt and infection middle ear 3. receives sounds and sends them through the auditory canal to the eardrum inner ear 4. a thin membrane that transmits sound waves into the middle ear cerumen 5. where the cochlea is sound waves 6. a snail-shaped organ lined with hair cells cochlea 7. inside, small bones transmit sound waves from the eardrum to the inner ear eardrum 8. destroyed by extended exposure to loud noise outer ear

Why is cancer dangerous or harmful?