A:改善土壤通气,根细胞呼吸加强
B:可增加土壤中N2的含量
C:改善土壤通气,硝化细菌繁殖快,有利于土壤中硝酸盐增加
D:可促进氨的扩散
如图是签订《南京条约》时的情景图,这一事件及此后可能出现的历史情景是
Over the past years, scientists have made many great b____ in science and technology.