Read the following passage and mark the letter A, B, C, or D on your answer sheet to choose the word or phrase that best fits each of the numbered blanks from 27 to 31.

Psychologists tell us that humour and laughter are good for our social relationships. Having a good (27) _______ of humour is often regarded as being one of the most important characteristics that people look for in a friend. In classrooms, a humorous teacher can make learning far more enjoyable and improve a student's (28) _______ .
In one study, students on a psychology course are split into two different groups: one group was taught with a certain amount of humour, and (29) _______ group with no humour at all. Later, when researchers tested the students to see how much they had retained of what they had heard in the lectures, they found that those (30) _______ had attended lectures containing humour scored significantly higher than the other students. Humour and laughter make us feel happy, and our laughter makes others laugh as well, (31)_______ if we laugh a lot we may be helping to make other people feel happy.
(Adapted from Cambridge English First for Schools)