固位形
参考答案：
能使修复体获得抵抗外力而不知脱落和移位的能力的几何形状。
汽车行驶是______现象，风车转动是______现象．
My parents are workers. _____ both work in the same factory (工厂). [ ]
A. Them
B. They
C. He
D. She
