It has been proved_______eating vegetables in childhood helps to protect you against serious

illnesses in later life.[ ]

A. if                        

B. because

C. when                      

D. that

急性化脓性腮腺炎病因最主要是（）

A.异物

B.外伤

C.免疫缺陷

D.脱水及逆行感染

E.腮腺先天性结构异常