欲配制PH=10的缓冲溶液选用的物质的组成是()。
A.NH3-NH4Cl
B.HAC-NaAC
C.NH3-NaAC
D.HAC-NH4
参考答案:A
We all hope that our head teacher is both strict _____ us and friendly _____ us. [ ]
A. in, to
B. in, for
C. with, to
D. with, for
植物病原细菌的形态为()
A.球状
B.杆状
C.螺旋状
D.星状