11. adequate precautions are take, there is no risk involved in the operation.

　　a. Although c. Nevertheless

　　b. Providing d. Even

　　12. My supervisor advised me to the problem.

　　a. look ahead c. look out of

　　b. look down d. look into

　　13. The more acid you add to the solution, it becomes.

　　a. cloudier c. the cloudiest

　　b. the cloudier d. more cloudy

　　14. The lecturer said ‘It’s time you the literature review.’

　　a. began c. should begin

　　b. begin d. are beginning

　　15. After studying our experimental results, the tutor suggested the experiment.

　　a. us to repeat c. we repeat

　　b. that we to repeat d. me to repeat

　　16. After your results you should make an appointment with your tutor.

　　a. you receiving c. you have received

　　b. you would have received d. you received

　　17. You the experiment twice, not once.

　　a. should have carried out c. haven’t carried out

　　b. shouldn’t have carried out d. couldn’t have carried out

　　18. It looks you’ve made a mistake.

　　a. as c. if

　　b. as though d. perhaps

　　19. After receiving her results, the student stopped .

　　a. to worry c. worrying

　　b. having worried d. to be worried

　　20. You include this section. It is not necessary

　　a. must c. don’t need

　　b. couldn’t d. don’t have to