- Home
- Teachers
- Users
- Dictionary
- Tools
- Mstory
- Story
- Notebook
- QA
- Video
- My Community
- My Lesson
- My Wallet
- Buy CSP
- Profile
- Settings
- Submit a Ticket
- My Ticket
- Help
- Log off
Correct
溶洞
/ róngdòng /
Strokes
Definition
karst cave
Example
As a Noun
limestone/karst cave
As a Noun
dissolved cavern