Choose the best option to complete the following sentences. (3ms) 1. The teacher said you should work harder........................your English grammar. A. of                                B. on                           C. about                         D. with 2. The scientist and his assistant conducted many........................in the laboratory. A. exhibitions                  B. inventions           C. experiments         D. encouragements 3. You must cover........................sockets so that children do not try to put anything into them. A. suitable                       B. sociable                   C. immediate                  D. electrical 4. Revision is really........................in learning English. A. fortunate                    B. necessary                C. greedy                       D. generous 5. Choose the word that has the underlined part pronounced differently from that of the others. A. heard                          B. heart                       C. earn                            D. earth 6. The teacher told me........................ part in volunteer work. A. take                            B. taking                     C. to take                        D. took 7. The concert was boring. It was........................concert I’d ever seen. A. the most boring B. most boring                 C. more boring         D. the more boring 8. The doctor said he........................stay up late. A. will                             B. has to                      C. should                        D. shouldn’t 9. - Can you help me? A. What can I do for you?                                  B. No, thanks. C. Yes, please                                                     D. That’s very kind of you. 10. My father used to live........................a farm when he was young. A. in                                B. for                           C. at                               D. on 11. Some language learners write each word and its use on a small piece of paper and stick it somewhere in their house........................learn it at any time. A. to                                B. so as to                   C. in order to        D. All are correct. 12. - May I help you? A. Sure.                           B. No. Thank you.      C. No problem.               D. Of course.