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| метрополитен (A metro system is a rapid transit train system. In some cases, metro systems are referred to as subways or undergrounds. The first metro system, the London ... WK. St Petersburg's metro system, which is used by more than two million passengers every day, has not suffered previous attacks. BBC Alexander Demidov) | |||
| metro system: 1 phrase in 1 subject |
| Ecology | 1 |