颈内动脉血流频谱是下列哪种表现
A.低阻力频谱
B.高阻力频谱
C.舒张期三峰频谱
D.宽频毛刺样频谱
E.窄频三峰递减型频谱
参考答案:A
下列各分子中,中心原子为sp3杂化的是:()
A.H2O
B.BF3
C.SiCl4
D.PCl3
下列数组声明语句中,正确的是
A.Dim A [3,4] As Integer
B.Dim A (3,4) As Integer
C.Dim A [3;4] As Integer
D.Dim A (3;4) As Integer