按照国家标准GB 50010－2002《混凝土结构设计规范》，混凝土强度等级应按立方体抗压强度标准值确定。立方体抗压强度标准值系指按标准方法制作和养护的边长为150mm的立方体试件，在28d龄期用标准试验方法测得的具有95％保证率的抗压强度，以fcu，k表示。普通混凝土划分为十四个强度等级：C15、C20、C25、C30、C35、C40、C45、C50、C55、C60、C65、C70、C75和C80。混凝土强度等级是混凝土结构设计、施工质量控制和工程验收的重要依据。不同的建筑工程及建筑部λ需采用不同强度等级的混凝土，一般有一定的选用范Χ。-I like　it.But you　do not　know.The plant fungal pathogen Fusarium graminearum is the causative agent of Fusarium head blight in wheat and Gibberella stalk rot in maize. It not only causes severe yield loss, but also contaminates grain with its mycotoxins such as deoxynivalenol (DON) that are harmful to humans and animals. Genetic source of complete resistance to F. graminearum in cereal crops is not available to date, which highlights the importance in developing novel solutions based on in-depth understanding of its pathogenicity. So far, F. graminearum pathogenicity in wheat head blight has been extensively studied, whereas little is known about its pathogenicity in maize stalk infection.