下列有关G蛋白的描述错误的是
A.与GTP或GDP结合
B.位于细胞膜胞液面
C.由α、β和γ三个亚基组成
D.G蛋白有非活化型、活化型和功能型三种构象
参考答案:D
函数y=ax2+c(a≠0)的图象的对称轴是______;顶点坐标是______.
It suddenly_________to the detective that the millionaire was probably murdered. [ ]
A. happened
B. occurred
C. thought
D. took place