Don't you think it necessary for us ____     the teacher for hel.p:l            [ ]

A. to ask                

B. ask                

C. asking

肾病综合征患者必有的临床表现是

A．大量蛋白尿和低蛋白血症

B．大量蛋白尿和水肿

C．水肿和高脂血症

D．高脂血症和高血压

E．低蛋白血症和血尿