下列属于一次污染物的是（）。
A.NH3
B.H2S04
C.过氧乙酰硝酸酯
D.N02
参考答案：A
踝关节跖屈的正常活动度是（）A.0°～30°B.0°～35°C.0°～40°D.0°～45°E.0°～50°
踝关节跖屈的正常活动度是
A.0°～30°
B.0°～35°
C.0°～40°
D.0°～45°
E.0°～50°
In relation to the Labour Contract Law of China:
(c) State the restriction on the duration of time for a non-competition clause in a labour contract. (3 marks)
