皮肤中含有各种电解质,其中可维持细胞膜的通透性和细胞间粘着的是()
A.Na+
B.Cl-
C.Zn2+
D.Ca2+
E.K+
参考答案:D
___ is an engineer.
A.Li Pin’s and Li Hua’s father
B.Li Pin and Li Hua’s father
C.Li Pin’s and Li Hua father
D.Li pin and Li Hua father
坡度一定,转弯速度增加时转弯率和转弯半径如何变化?