古诗词默写。(6分) ①曲径通幽处, 。(常建《题破山寺后禅院》) ② ,玉垒浮云变古今。(杜甫《登楼》) ③“梦”,是温馨的怀想,是美好的期盼。温庭筠在《商山早行》中用“因思杜陵梦,凫雁满回塘”抒发了他的思乡之情;李白在《行路难》中用 “ , ”表达了他希望得到重用的愿望。 ④时代的进步,需要劳动来成就;梦想的If people ______ the importance of living a low-carbon life earlier, there ______ so many environmental problems now. A. had realized; wouldn’t be B. realized; wouldn’t be C. had realized; wouldn’t have been D. realized; wouldn’t have been