将实验效应与公认的标准值或正常值作对照的是()
A.空白对照
B.实验对照
C.标准对照
D.自身对照
E.相互对照
参考答案:C
How do you study _____ a test? -- I study _____ making flashcards
A.by, for
B.for ,for
C.for , by
D.by , by
肺癌的早期表现是()
A.咳嗽、咳血痰
B.颈、面部水肿
C.持续性低热
D.咳嗽、咳脓痰
E.持续性胸痛