自左向右投影,在正面上所得到的图形为()。
A、主视图
B、俯视图
C、左视图
D、右视图
参考答案:C
Dina, _____ for months to find a job as a waitress, finally took a position at a local advertising agency. [ ]
A. struggling
B. struggled
C. having struggled
D. to struggle
下列因素,对电导率测定有影响的是()。
A.溶剂的性质
B.溶液的浓度
C.电极的极化
D.电导池存在电容