`20,` This report ____________ on my desk first thing this morning. Now the deadline has passed and the boss is very dissatisfied. A. might have been B. could have been C. was to have been D. must have been `21,` - Peter: "I wish I hadn't said those things to her." - Julia: "Don't worry about it! You _____________ it. I'm sure she understands you didn't mean any harm." A. should have regretted B. needn't have regretted C. must be regretting D. mightn't have regretted