Whilst credit must be given to the Museum of Coastal Defence (well worth visiting) and to the Tourism Board for providing guided tours around Wong Nai Chung Gap and Pinewood Battery, there is precious little other information regarding the numerous other sites that dot the countryside and are in an advanced state of decay.

I ask our government to act quickly and to invest some of the HK$500 million already earmarked for the heritage conservation scheme from this year's budget into preserving these sites so that future generations may also have the pleasure of seeing them before they crumble away.

C. Mitchell, Ap Lei Chau

What do you think of the building grading system?

I think the grading system for buildings of the Antiquities and Monuments Office has advantages and disadvantages.

The advantages are to enable people to know which buildings are historic, and to identify the ones that have been declared monuments. These buildings can then attract a lot of visitors and this is good for Hong Kong's economy.

Having the grading system can help students with their history lessons. It is easier for them to find these buildings.

The downside to the system is that buildings that are graded are not protected, unlike a building that has been declared a monument. A graded building may still be demolished and this is where the system is clearly flawed.

If a building is inhabited and is to be demolished, then residents will have to move out and this may cause a great deal of discontent.

I think the government should act in order to protect these buildings, otherwise the grading system is useless.

Edison Cheung Fu-ho, Sha Tin

How can the use of electric cars be promoted?

The idea that electric cars could be used in Hong Kong is a pipe dream. Electric cars are unable to replace conventional petrol or diesel versions, as they take too long to recharge.

A combustion-engine car is ready to go any time. If you need fuel you go to a filling station and fill up in minutes, not hours like with electric cars. But the biggest hurdle that promoters of electric cars miss is: how will ordinary people recharge their cars?

Many people live in tower blocks with their cars parked either in lower levels, or some distance away in a cheaper parking lot. Who is going to supply all the electrical points for these vehicles? The building or lot owners?

Does this mean cables trailing everywhere across pavements as people who do not have a parking space try to recharge? The electric car is not a suitable replacement in its present form.

To be successful in a market a product has to at least match the product it is going to replace. A replacement car should be able to be refuelled quickly and parked anywhere.

Hybrid cars go some way to reducing pollution, but if the vehicle is large or full, then the combustion engine is running to compensate for the extra loads and producing pollution.

Other systems, like hydrogen fuel cells, would be a much better avenue to explore before backing a product nobody will want.

Brian Slade, Sha Tin

Problems caused by greenhouse gas emissions and the increased demand for fossil fuels for vehicles are contentious subjects. Environmentalists and scientists have suggested that drivers replace normal cars with electric cars, which are thought to be more environmentally friendly. However, it will take a real effort to make electric cars part of our daily lives and ways will have to be found to promote these cars.

Obviously, these electric cars can be advertised through television and radio, leaflets can be distributed and posters put up.

After a brief introduction, the adverts should compare an electric with an ordinary car, to try to get potential customers' attention.

Also, the government and public transport companies should lead by example. They could organise demonstrations of electric vehicles for the public.

I think over the next few years, demand for electric cars will increase.

Paul Yim, Sha Tin