Why londoners keep black rivers in the tower of london

first of all, not rivers but ravens (вороны).

londoners keep black ravens in the tower of london because there is an old legend that says if the ravens ever leave the tower of london - the white tower would crumble and a great disaster shall befall kingdom. that is why people who work there, take care of ravens. i also can add that the ravens' wings are kept short so they couldn't fly away.

Ihave been digging the garden since morning my father has been working for three hours i have been writing thus article for about an hour and a half. my sister and have been cleaning our house since morning your hair are wet. have you been swimming? children, your shoes are dirty. have you been playing in the yard? i've been watching this film for about an hour my mother has been doing her job for two hours. the washing machine has been washing the clothes for two hours i've been writing a script for several days our family has been working in the garden since 11 o'clock my friend has already been talking on the phone for about twenty minutes my little brother has been learning the poem for two hours my granny has been knitting a scarf for me for a week my cat has already been playing for ten minutes

1does the emblem of the university consist of a medical cross,a textbook,a cup and a snake? -общий вопрос 2does the emblem of the university or the institute consist of a medical cross,a textbook,a cup and a snake? -альтернативный вопрос 3what consists of a medical cross, a textbook, a cup and a snake? - вопрос к подлежащему 4what does the emblem of the university consist of? -специальный вопрос 5the emblem of the university consists of a medical cross,a textbook a cup and a snake, doesn't it? -разделительный вопрос