Read the following passage and mark the letter A, B, C, or D to indicate the correct word that best fits each of the numbered blanks.

    The ideal breakfast, say scientists, is a glass of orange juice, a cup of coffee and a bowl of cereal. People who start the day with a drink of vitamin c, a dose of caffeine and their favorite cereal are happier and perform better (23) ________ the morning. Andy Smith, of the University of Bristol, said, “A study of 600 people who were asked to record their breakfast (24) ________ found that those who regularly ate cereal in the morning had a more positive mood compared with those who ate other foods or had no breakfast. Earlier research had shown that people whose (25) ________ performance was measured immediately after eating breakfast of any kind performed 10 percent better on test of remembering, speed of response and ability to (26) ________, compared with those given only a cup of decaffeinated coffee." In further research, Professor Smith said that people who drank four cups of coffee a day performed more (27) ________all day than those who drank less. He suggested that sensible employers should give out free coffee or tea.