diver’s lifeline with a cable for video and data (e.g. for a depth sensor) and a separate communication cable.

How would the previous sentence be correctly capitalized?
Answer: Diver’s lifeline with a cable for video and data (e.g. for a depth sensor) and a separate communication cable.
there are many sculptures and busts from the communist era.

How would the previous sentence be correctly capitalized?
Answer: There are many sculptures and busts from the communist era.
on saturday it will be sunny during the day. the night will bring mainly cloudy, but mostly dry weather. morning temperatures will be around 11 °c. during the day they will reach a maximum of 17 °c. low temperatures at night will be around 12°c. we have moderate to brisk westerly wind with strong gusts.

How would the previous sentence be correctly capitalized?
Answer: On Saturday it will be sunny during the day. The night will bring mainly cloudy, but mostly dry weather. Morning temperatures will be around 11 °C. During the day they will reach a maximum of 17 °C. Low temperatures at night will be around 12°C. We have moderate to brisk westerly wind with strong gusts.
this event is sometimes called the "cambrian explosion", because of the relatively short time over which this diversity of forms appears. some point to the increase in oxygen that began around 2 billion years ago supporting a higher metabolic rate and allowing the evolution of larger organisms and more complex body structures.

How would the previous sentence be correctly capitalized?
Answer: This event is sometimes called the "Cambrian Explosion", because of the relatively short time over which this diversity of forms appears. Some point to the increase in Oxygen that began around 2 billion years ago supporting a higher metabolic rate and allowing the evolution of larger organisms and more complex body structures.