the classic boxes, too, feature variable fastening and the double-action dual-force opening mechanism.

How would the previous sentence be correctly capitalized?
Answer: The Classic boxes, too, feature variable fastening and the double-action Dual-Force opening mechanism.
one of the big issues in the gdpr is how data comes in. here are two options:

How would the previous sentence be correctly capitalized?
Answer: One of the big issues in the GDPR is how data comes in. Here are two options:
this town in the valley of the sieve has given the chianti, which grows on the surrounding hills, its name: chianti rufina.

How would the previous sentence be correctly capitalized?
Answer: This town in the valley of the Sieve has given the Chianti, which grows on the surrounding hills, its name: Chianti Rufina.
high ablation resistance, high toughness, good electrical and heat conductivity of tungsten copper provide necessary conditions to stable operation of the discharge tube.

How would the previous sentence be correctly capitalized?
Answer: High ablation resistance, high toughness, good electrical and heat conductivity of tungsten copper provide necessary conditions to stable operation of the discharge tube.