I don't know What 'for which' is means and why it is used in this line He played a leading role in the Mariner, Viking and Voyager expeditions to the planets, for which he received the NASA medals for Exceptional Scientific Achievement and for Distinguished Public Service, and the international astronautics prize, the Prix Galabert. I'ts from Cosmos the book I though I was certain that I am quite familiar with 'which and that', that called relative pronoun. but sometimes a relative pronoun accompanied with preposition takes me nowhere like for which, by which, in which. Because I am intimately familiar with Korean so If anybody can explain in Korean then that must be more helpful than in other language but not that you should answer me in Korean.

Hello, I'd like to say.. something. Hello, I'am Roh, I just got here and This is going to be my second notebook, I have studied English for almost 8 years through Schools but still I'm poor at English. At first, Me and English couldn't get along because when I was in middle school, teachers gave me the wrong impression that English is nothing but all grammar and If you don't memorize how grammar works you will not able to use English and that impression remained until I started to listen the songs that its lyrics are in English. One day in my high school, the thought downed to me when i was listening to Mushaboom from Feist, who are Canadian, that 'Would’t it be nice If I could understand what's she saying?' and that was the moment after 6 years when Me and English get united first time in my life. Since then I have studied hard, watched several TV shows that are obviously in English by way of excuse of improving my English skills, read a few books that are also in English, listened more songs that are in English too and I eventually ended up being a college student who's major is English. So It's no wonder that I love Leslie Feist so much. By the way now I know what The lyrics in Mushaboom mean so that I can love Mushaboom more than before. Here's what I am going to do for improving my English. Read a book I have already set the book that I'm going to read, that is The ultimate guide to hitchhiker, first I watched Movie version of this and It caught my attention so I've decided I know It's really really thick book. so I'll need your help. hope you can help me. Thank you for reading this.