Complex sentence: Samsung Group accounts for more than 20% of South Korea's total exports, and in many domestic industries, Samsung Group is the sole monopoly dominating a single market, its revenue as large as some countries' total GDP.
Split into simpler sentences: Samsung Group accounts for more than 20% of South Korea's total exports. In many domestic industries, Samsung Group is the sole monopoly dominating a single market; its revenue as large as some countries' total GDP.