Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Year | Tournament | Venue | Result | Extra |
| --- | --- | --- | --- | --- |
| 1997.0 | World Indoor Championships | Paris , France | 3rd | 4x400 m relay |
| 1997.0 | World Championships | Athens , Greece | 1st | 4x400 m relay |
| 1998.0 | European Championships | Budapest , Hungary | 1st | 4x400 m relay |
| 1998.0 | World Cup | Johannesburg , South Africa | 1st | 4x400 m relay |
| 1999.0 | World Championships | Seville , Spain | 3rd | 4x400 m relay |
Question:
What extra has world championships as the tournament, and 1st as the result?
Answer:
4x400 m relay