1. Because charging facilities not yet universal. <br>2. Reducing exhaust emissions <br>3. To the owners are willing to cooperate or IO has been difficult <br>4. inadequate
1. Because charging facilities are not available for the time being.<br>2. Less discharge<br>3. It is difficult for the owners or IO to be willing to cooperate<br>4. Insufficient
1. Because the charging facilities are not popularized temporarily.<br>2. Reduce exhaust gas<br>3. It is difficult for the owners or IO to cooperate<br>4. deficiency