1. Get to the root of the matter：(6) Phew 哟, 表示不快的声音 | (7) Get to the root of the matter 刨根问底 | (8) Plausibly 似真的
2. Is this a plane：15. 猜价钱--How much is it? | 16. 刨根问底--Is this a plane? | 17. 老狼老狼,几点钟--What time is it?
3. to get to the root of things：救死扶伤--to heal the wounded and rescue the dying | 刨根问底--to get to the root of things. | 开源节流--to increase income and reduce expenditure.