At present , the terrible foggy haze（雾霾）weather has influenced our normal life badly . So our government should _____ to reduce the air pollution.

A．put out

B．carry out

C．take steps

D．get over

设有5个产地A1、A2、A3、A4、A5和4个销地B1、B2、B3、B4的运输问题，它们的供应量与需求量及单位运费表如表所示。

A．970
B．960
C．870
D．830