QUES: He spent a year abroad then in 1903 he returned to become a professor at Moscow University

correct the punctuation.

CORRECTED: He spent a year abroad, then in 1903 he returned to become a professor at Moscow University.

QUES: Similar games to Rusty Spot the Difference

correct the punctuation.

CORRECTED: Similar games to Rusty - Spot the Difference

QUES: Luminance difference Indicates the transition between light and dark surfaces

correct the punctuation.

CORRECTED:
Luminance difference Indicates the transition between light and dark surfaces.