When we got to the top of the hill, the sun __
A.was shining
B.shone
C.has shone
D.shines
答案:A
以下哪个量表属于自评量表()
A.Barthelindex
B.FIM
C.SCL-90
D.GCS
E.MAS
简述色氨酸操纵子的阻遏系统和弱化系统?