About how can i graduate with high diploma?

i am a student of high school.now i am a sopre.when i came i was freshmen. i came from Bangladesh in February 2009. than i start my school from march. the reason is in my country the school start from January and end at December i just ped 8th grade from my country. but when i came i saw that they r starting second term. when the ask me about my report card i showed them my 8th grade one. then they asked me abut my first term report card for 9th grade. but i don't have it. that's why my 7th cradits are missing. i wanna earn them. after that i wanna earn some extra cradit. how can i do that. if you help me i will really appreciate and thanksfull to you guys