用酸度计测量液体食品的pH值时,指示电极是()
A、玻璃电极
B、金属电极
C、标准氢电极
D、甘汞电极
参考答案:A
Many people are here ______ vacation, so it's very crowded. [ ]
A. in
B. at
C. with
D. on
(本题6分)比较教育研究中依赖理论的基本观点是什么