In Moscow, there are approximately 35,000 dogs living on the streets. Some of these ___HOME___ animals were born there. Others are just ___LUCKY___ pets that have been abandoned by their owners. For many dogs the city may be a ___DANGER___ place to live in. However, scientists were surprised to find out how ___EASY___ some animals can adapt to urban life. Some dogs have even learnt to use the city’s metro system! We still don’t know how the dogs find out when to get off the train. One ___SUGGEST___ is that they use their excellent sense of smell to recognise the scents of their favourite destinations. Another idea is that they are able to remember the design of ___DIFFER___ stations and find the station they need.