 |
| |||
| direct instruction | |||
| direct guidance | |||
| 直接 指导: 3 phrases in 2 subjects |
| Aviation | 1 |
| Space | 2 |
The server is undergoing maintenance and the site is working in read-only mode. Please check back later.">Add | The server is undergoing maintenance and the site is working in read-only mode. Please check back later.">Report an error
| Get short URL | Language Selection Tips