Add punctuation: Holiday House for rent Munkebo Denmark From vacation rental agency
A: Holiday House for rent Munkebo Denmark - From vacation rental agency

Add punctuation: In the 1970s industrial relations was very important
A: In the 1970's industrial relations was very important.

Add punctuation: After returning to Cambridge in 1938 Smithies taught at St Johns College and continued his research
A:
After returning to Cambridge in 1938, Smithies taught at St John's College and continued his research.