He most serious effect of the poor sanitation and contaminated water supplies in tenements was filthy living conditions. a cholera epidemic. a public-health problem. immigrants were unable work.

A cholera epidemic.

Explanation:

The cause of cholera is scientifically proven or believed to be from contamination of foods or drinkable water in which humans later take into their body system. This is often common where there is an inefficient water supply system.

Hence, in this case, the most serious effect of the poor sanitation and contaminated water supplies in a tenement ( a typical large building, which is occupied by quite a several people) is "a cholera epidemic."

the catholic church withhold people's access to the bible during the middle ages.

people could go to church and listen to the teachings, but it was absolutely forbidden to own and/or read the books of both the old and new testaments. it was also prohibited to translate the books (which where originally in biblical hebrew) to any other language.

this was done so the church could remain in control of what their teachings were and to enhance their importance and power, while also being able to judge people's actions through information that was unavailable for the general public.

this forms a narrow, steep sided inlet (sometimes deeper than 1300 metres) connected to the sea. the terminal moraine pushed down the valley by the glacier is left underwater at the fjord’s entrance, causing the water at the neck of the fjord to be shallower than the main body of the fjord behind it.