Find a mistake in each sentence below

II. find a mistake in each sentence below
17. the stone stelue was engraved with the names of the top students in royal examinations
                                   A                     B                                         C         D
18. everybody in the house was asking questions after the thief had left
                        A                          B                 C                                   D
19. hue imperial city was certified as a world cultural history in 1993
                                   A                  B                               C             D
20. the factory use the most modern production methods
                        A             B                       C                D
21. one pillar pagoda was built in emperor ly thai tong in 1094
                                    A            B                    C              D