Question

decide whether each sentence is punctuated correctly. use the drop-down menus to choose which revisions, if any, are necessary.
when you go to the supermarket, please buy eggs, milk, pears, and carrots.
no revision needed
i plan to go skiing with my sisters, charles and boris.
add a comma after and
add a comma after charles
no revision needed

Explanation:

1. For the first sentence: The introductory dependent clause "When you go to the supermarket" is correctly set off with a comma, and the series of items uses the Oxford comma correctly, so no revision is needed.
2. For the second sentence: "Charles and Boris" are restrictive identifiers specifying which sisters (they are the sisters, not additional people), so no commas should be added. The original punctuation is correct.

Answer:

1. When you go to the supermarket, please buy eggs, milk, pears, and carrots.: no revision needed
2. I plan to go skiing with my sisters, Charles and Boris.: no revision needed