1) I am keen to pursue a career in engineering , and the advertised position would offer me the perfect opportunity for career advancement . 2) I am proficient in MS Word, Excel (,) and Powerpoint , and I pick up new skills easily. According to most style manuals, you are wrong to omit commas from between the clauses of a compound sentence (which both of those are), and in addition, if you wish to be clear, I think you should use them here anyway.
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