Therefore they held an emergent meeting to discuss their countermeasure. They immediately decided to send the small tortoiseback to fetch the umbrellas.
于是它们召开紧急会议讨论对策，并且马上决定派一只乌龟回去取雨伞。
2
A tortoise has a shell on his back.
乌龟背上有硬壳。
《新英汉大辞典》
3
The earliest written forms of Chinese in existence today date back nearly 4, 000 years.// These writings are incisions on bones and tortoise shell.