Помогите срочно, пожалуйста!!!

1. She sank (back/down) on the pillow and closed her eyes. 2. His voice sank (to/in) a conspiratorial whisper. 3. The implication of his smile took a while to sink (in/back). 4. That revenge he had been suffering from sank (in/to) his heart. 5. Sam is absolutely broke, he even sank (to/in) robbing his own friends. 6. The government was ready to let the pound sink (in/to) parity to the dollar. 7.She entered the room and immediately sank (down/back) into the armchair standing close to the door. 8. He paused to let the point sink (back/in). 9. Before he continued he sank (to/back) in his chair. 10. Anything said to him wouldn`t sink (in/to)