Low-toxic pesticides can not be sprayed

At present, many farmers use pesticides instead of measuring cups, but follow the feelings and even mix three or four kinds of pesticides together, thinking that this can achieve good control effects. However, I do not know that this method of medicine not only

How explosion-proof lamps work

The working principle of explosion-proof lamps is that substances change from one state, through physical or chemical changes, suddenly to another state, and emit huge energy. The energy released by the sharp speed will cause the surrounding objects to be subjected to viole