Where's my pen? [ ]
A. It's in the desk.
B. It's under the desk.
C. It's on the desk.
答案:B
溶胶剂所特有的性质有()
A、丁铎尔现象
B、胶粒的双电层
C、胶粒的水化膜
D、布朗运动
E、电泳现象
悬臂拼装法