Which editing mark signifies you are inserting a word?

choose the correct spelling

Which of the following is not spelled correctly?

Which sentence demonstrates correct apostrophe use?

The company will upgrade ______ computer systems next week.

True or false? There is a mispelled word in this sentence.

___ disagree on the facts.

What do you call this punctuation mark: "..."?

What happened in the race?

Which word is incorrect? If your pants are to loose you might lose your pants.

Which of the following sentences does not contain any errors?