1. keeping up with the rest of the class.

　　2. none of us expected the chairman to turn up

　　3. as was to be expected

　　4. an art as it is a science

　　5. could have made a good salary.

　　6. to have no access

　　7. to students’ being late for

　　8. ranges/varies from 50 cents to $4

　　9. to reserve a table for

　　10. to make trouble

　　11. at intervals

　　12. injure himself

　　13. busy preparing for

　　14. had to be operated manually

　　15. needn’t have borrowed it from the bank.

　　16. shall have left for

　　17. is often a very time-consuming job

　　18. something was done/some measures were taken

　　19. overcame it/got over it

　　20. in the way

　　21. had interrupted me

　　22. it is because she is too inexperienced

　　23. caught him cheating me

　　24. did not work in the same office

　　25. was finally called off/cancelled because of the bad weather

　　26. will be doing/conducting the experiment

　　27. has a strong influence on