等边三角形绕着它的中心至少旋转( )度后能与自身重合.
120
Jack has had no______ experience of this kind of job,but he got the job offer just due to his honesty.
A.obvious
B.cautious
C.previous
D.precious
氧化锌的分子式是()。
A、CuO
B、ZnO
C、K2O
D、MgO