Beijing weather 2.5 query

(1) Increasing the greening of urban roofs can purify the air and play a positive role in the management of PM2.5;

(2) Strengthening the supervision of dust on construction sites and roads can reduce PM2.5 particles and play a positive role in the control of PM2.5;

③ The development of urban rail transit and bus rapid transit can reduce the emission of air pollutants and play a positive role in the control of PM2.5;

(4) Strictly investigate and deal with burning garbage and straw, which will reduce the generation of harmful gases and dust and play a positive role in PM2.5 control.

Therefore, choose: d.