Exercise 7: Choose the best answer: 1, Who’s the man _________ that photograph?    A. in                                        B. on                                    C. at                                     D. to 2, Some people like to sit ____________ the front row.    A. in                                       B. on                                    C. at                                      D. to 3, Turn left ___________ the traffic light.    A. in                                       B. on                                    C. at                                     D. to 4, We’ll meet Henry ____________ the entrance of the palace.    A. in                                       B. on                                    C. at                                     D. to 5, There is a notice ________ the door. It says “Do not disturb!”.    A. in                                        B. on                                    C. at                                     D. to 6, I’ve been ___________ Australia 3 times.    A. in                                       B. on                                    C. at                                      D. to 7, Children, get __________ the car and fasten the seatbelt.    A. in                                       B. on                                    C. at                                     D. to 8, What did you do _____________ last night, Joe?    A. in                                       B. on                                    C. x                                      D. to 9, I saw Steve __________ a concert __________ Sunday.    A. in/ on                                  B. at/ on                               C. at/ in                                D. on/ on 10, Water boils __________ 100 degree Celsius.    A. in                                       B. on                                    C. at                                      D. to