We are good friends. We ____each other since we were in the primary school. A know B knew C have known D have been known 2 Thanks ____the money he received , he was able to attend the university A on B for C of D to 3 Many words have been added ____this edition off the dictionary A for B from C to D in 4 ____ we use water economically , we won not have enough fresh water to use in the future A If B Unless C Because D Although 5 It is necessary ____uniforms when they are at school A with students to wear B for students to wear C for students wearing D to students wearing 6 He bought a new dictionary , but he did not tell me how much___ A did it cost B it costs B has it cost D it cost 7 ___ population is another unpleasant problem we have to solve A Increased B Increasing C The increasing D To increase 8 I think chatting on the Internet is_____ A required B compulsory C violent D time -consuming 9 Lan and her family had a ___ to their home village A two -days trip B day - two trip C two-day trip D day trips