23. In our class, when the bell rang and the teacher closed his book, it was a ______for everyone to stand up.
A. mark B. chance C. signal D. measure
24. A notice was ______in order to remind the students of the changed lecture time.
A. sent up B. given up C. set up D. put up
25. People try to avoid public transportation delays by using their own cars and this ______ creates further problems.
A. in short B. in turn C. in doubt D. in case
26. How much ______she looked without her glasses!
A. Well B. good C. better D. best
