いいまちがい2 / Wrong word 2

m_10
1. Mum…I have a toothache…
2. Ah! You have a back tooth!
3. I know. It’s a “REIKYU-SYA”(= a hearse) , isn’t it?
4. It’s a “EIKYU-SHI”(= a permanent teeth)…Lol.