Instructions: select all the correct answers.
proofread this persuasive passage on the importance of travel. which two types of errors does it contain?

travel is essential for our mental development. a recent study conducted by psychology professors found that regular travelers tend to be more open-minded than those who don’t travel regularly. it stated that travel introducted others to vast cultures, which them them adopt a more tolerant attitude. various studies and surveys conducted over time have also proved that regular travel boosts one’s self-confidence and self-relience.

spelling errors
incorrect comma usage
doubling of words
faulty use of apostrophe