 |
| |||
| half-value period | |||
|
半 值 期 : 5 phrases in 5 subjects |
| Business | 1 |
| Economy | 1 |
| Metallurgy | 1 |
| Space | 1 |
| Technology | 1 |
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