Final answer:
The given sentence needs to be punctuated correctly. The correct punctuation is: I can't make you pretty in the picture, so you mustn't be offended.
Step-by-step explanation:
The given sentence, I cant make you pretty in the picture so you mustnt be offended, needs to be punctuated correctly. Here is the corrected sentence:
I can't make you pretty in the picture, so you mustn't be offended.
Let me explain the punctuation changes:
- Added an apostrophe in 'can't' to indicate the contraction of 'cannot'.
- Inserted a comma after 'picture' to separate the two clauses.
- Changed 'cant' to 'can't' for proper spelling.
- Added an apostrophe in 'mustn't' to indicate the contraction of 'must not'.
- Changed 'mustnt' to 'mustn't' for proper spelling.