David felt ________of the foolish thing he had done in the classroom.

 It is _______ of the students to stay up reading till late night before the final exam. 

Would it be ___ for you to pick me up at four o’clock and take me to the airport? 

—How is your recent trip to Sichuan? —I’ve never had ______ one before.

    that the government can lead them out of the finacial crisis, people are optimistic about the future of the country.