Journalize and post to the allowance account the following events and transactions in the year 2021. (Credit account titles are automatically indented when amount is entered. Do not indent manually.) (1) On March 31, a $1,000 customer balance originating in 2020 is judged uncollectible. (2) On May 31, a check for $1,000 is received from the customer whose account was written off as uncollectible on March 31.