the evening will bring nearly cloudless weather. morning temperatures will be around 2 °c. during the day they will reach a maximum of 13 °c. low temperatures at night will be around 5°c. we have weak westerly winds.

How would the previous sentence be correctly capitalized?
Answer: The evening will bring nearly cloudless weather. Morning temperatures will be around 2 °C. During the day they will reach a maximum of 13 °C. Low temperatures at night will be around 5°C. We have weak westerly winds.
very little of the original human cultures have survived.

How would the previous sentence be correctly capitalized?
Answer: Very little of the original human cultures have survived.
over the last eight years it is clear that any residual lymphoma left over from the last treatment in 2008 has regressed to being imperceptible.

How would the previous sentence be correctly capitalized?
Answer: Over the last eight years it is clear that any residual lymphoma left over from the last treatment in 2008 has regressed to being imperceptible.
this does not prove that he was born in lassahn - only that he knew somebody in lassahn well enough for them to vouch for him.

How would the previous sentence be correctly capitalized?
Answer: This does not prove that he was born in Lassahn - only that he knew somebody in Lassahn well enough for them to vouch for him.