question: the corrosion resistance of stainless steel mainly depends on its alloy composition (chromium, nickel, titanium, silicon, aluminum, manganese, etc.) and the internal organizational structure, play a major role is the chromium.
Capitalize this past sentence correctly.
A: The corrosion resistance of stainless steel mainly depends on its alloy composition (chromium, nickel, titanium, silicon, aluminum, manganese, etc.) and the internal organizational structure, play a major role is the chromium.

question: avoid oil-based facial creams.
Capitalize this past sentence correctly.
A: Avoid oil-based facial creams.

question: after completing the third volume cantor realised that, at the age of 69, he was not up to the task of completing another volume, so at the congress of 1904 in heidelberg he organised a team with nine further contributors to collaborate on the fourth volume.
Capitalize this past sentence correctly.
A: After completing the third volume Cantor realised that, at the age of 69, he was not up to the task of completing another volume, so at the Congress of 1904 in Heidelberg he organised a team with nine further contributors to collaborate on the fourth volume.