Tham khảo :

Nowadays, pollution is a popular term with everyone in the world and air pollution is one type of pollution. The definition of air pollution is one such form that refers to the contamination of the air, irrespective of indoors or outside. A physical, biological or chemical alteration to the air in the atmosphere can be termed as pollution. There are some main reasons which cause air contamination such as burning of fossil fuels, agricultural activities, exhaust from factories and industries, mining operations, and indoor air pollution. Air pollution always has bad effects on our life. Harmful gases, dust, and smoke enter into the atmosphere and make it difficult for plants, animals and humans to survive. We also can see some examples of the result of air contamination which occurs around us as global warming, acid rain, and depletion of ozone layer. The effects of air pollution are alarming, so governments over the world should have suitable policies of protecting the environment, especially air quality to create a clean world for our generation in the future.

Nowaday, traffic problem is the biggest problem that many people care about. In VN, I think the city where have the worst traffic is Ha noi. 
The first problem is the traffic jam here. Why? In the rush hours of the day, there're too many people using the road. Last year, in 2013, many bridges was built so it happen less but in order to stop this, a kind of small car should be invented, people should go to works by buses instead of going by motorbikes...  
The second one, as you know, the roads in VN is not as big and clean as the roads in the big countries. They're narrow, bumpy and some dirty so it’s really hard for the road users to drive safely. I think we should raise money to make the road in VN better and better.  
But everyone knows that Vietnamese people are not respect and don’t follow the traffic rules. That’s the biggest reason for everything. They wear the helmet that not strong enough to keep they safe if the accident may happen, they ride too fast on the small roads… The traffic will never can be improve if they keep doing this.  
At the end, I hope the traffic in VN will improve more.

I live in Vietnam and there are a lot of traffic problems in big cities in my country. Firstly, there are too many people using the roads especially in the rush hour when people run out to work and school or get home from those places. Secondly, there are too many vehicles on the road that leads to traffic jams. Another problem is that many roads are narrow and bumpy. Fourthly, there are traffic accidents every day so a lot of people lose their lives or are injured. So in order to travel on the roads safely, I think we should obey the traffic rules and traffic signs as well. Moreover, carefulness is very necessary.

Traffic jam is not only a problem that Vietnam now has to deal with but also an issue needs overcoming in many other countries. Traffic jam is when there are too many transports moving on a road, and it often occurs in rush hours. We can see that in many cities. Due to a large population and poor infrastructure, with many personal motorbikes, Ha Noi is one of the cities in Vietnam must suffer from the traffic jam. Traffic jam has an influence on us: it leads to annoying and uncomfort. Moreover, the ozone layer is also affected by the carbon dioxide discharged. There are some solutions released to cope with this problem. But the most important way is from us. We ought to use public buses instead of personal transports so that trafic jam can be removed.

Chúc bạn học tốt!

Hanoi is very crowded and it has to face a lot of traffic problems. There are too many people using the roads. All types of vehicles are on the roads. It's very dangerous if you are not familiar with transportation here. There are some roads which are narrow and swampy when there is the heavy ram. Moreover, some young people drive on the road dangerously. They don't respect the traffic rules strictly and they even play on the street with their motors.

Of course, there are all different kinds of environmental problems and I do not know which problem you want discussed. I will write about global warming.

One of the major environmental problems today is global warming. It is caused by an excess of carbon dioxide in the atmosphere. This causes what is known as a "greenhouse effect."

The major effect of this greenhouse effect is to raise the temperature of the world as a whole. If this continues, climate patterns around the world will change. In addition, sea levels will probably rise, which will be bad for low-lying areas.

There are many possible solutions, all of them have to do with emitting less carbon dioxide -- either by using less energy or by finding energy sources that do not emit carbon dioxide.