单选题 The main idea of paragraph three is that ________.

【正确答案】 D
【答案解析】[解析] 主旨大意题。由文章的第三段第一句话,Most do not fully see this truth.Instead they complain about their problems and difficulties as if life should be easy.可知,人们经常抱怨生活是多么的艰辛。所以正确的答案为D。