（1）     富含的营养素是     ；

(2)                 其主要目的是    

                            食品包装时充氮                                         

(3) 缺少         肥（填化肥种类），该类化肥可增强作物           能力                                                                                                                                     

                                                                                                                         大豆叶边缘发黄                                                                               

（4）洗涤剂的作用是                                  。                                                                                        

用洗涤剂洗碗

答案

（1）蛋白质（2）防止食品腐败（3）钾（或K）抗病虫害和抗倒伏（4）乳化作用