根据句意，写出括号内所给单词的适当形式空。
It’s ______________ (possible) for dogs to fly. Stop daydreaming, Eddie.
Most children are afraid of real ______________ (mouse), but they like Mickey Mouse.
The poor boy’s parents have been ______________ (die) for years.
If you want to see some ______________ (Europe) buildings, Rome is a good place to visit.