Hi-tech gadgets may provide entertainment and be a sign of wealth, but they are not worth losing organs for. The man who sold his kidney to buy these gadgets regrets his decision as he is weaker and cannot work.

Stella Man Suet-ming, Pooi To Middle School

Runway will harm the environment

I do not approve of the construction of the third runway. While I agree that footing the bill using the user-pays principle would help the government shift the financial burden to frequent users, I wonder if the construction costs include the price of forsaking our precious environment.

Lots of green groups oppose this plan and have highlighted its serious consequences. For instance, the construction might devastate the marine ecology, not to mention the habitat of Chinese pink dolphins. But so far their appeals have fallen on deaf ears. The government should halt this plan. If the authorities insist on proceeding, the public should stand up to them.

Our environment is too precious to be ignored, and it needs to be safeguarded. If the government could propose an environmentally-friendly and more comprehensive plan, it might get more public support.

Michael Fong Yuk-ming, SKH Tsang Shiu Tim Secondary School

Is reading novels really good for us?

Most of my friends always have a thick book in their hands. They read all the time. From a teacher's point of view this might be a good thing because reading books can teach us a lot of new vocabulary and improve our writing skills.

However, too much reading is not good for us. Some people may skip lunch to read, and this is not healthy.

I also often see teenagers reading novels on public transport. When I did this for two months, I found that my eye-sight got worse, despite wearing my glasses.

Reading novels is good for us, but we must strike a balance. There's more to life than books.

Lois Ng, Our Lady of the Rosary College

Joint efforts needed to fight pollution

The article 'Guangdong waters still filthy' (SCMP, March 23) quoted an environmental report that found nearly 12 per cent of water in the province's estuaries was severely polluted. This is bad news. If environmental regulations had been effectively implemented, there should not be any polluted water. The central government needs to do more to improve water quality.

There are a lot of factories in Guangdong. The authorities need to increase penalties and inspections to stop the plants from illegally dumping untreated waste water. They must also raise public awareness of the importance of water resources.

Meanwhile, the poor water quality in the province, especially Shenzhen, could threaten Hong Kong's waterways and wetlands, as well as some of the endangered species in local rivers. Hong Kong needs to work with the central government to prevent this from happening.

Nicole Mok Wing-sum

How bathing differs across world

Recently, I read an article about different kinds of baths.

People in Japan sometimes bathe in hot sand, beer or curry. Azerbaijan has petroleum baths. And Sichuan offers mud baths. People also take baths in chocolate and red wine. They are said to be good for our bodies, enhancing our blood circulation and metabolism.

All these different practices represent a great range of cultures around the world. These differences make cultures unique. We can understand a culture and its traditions by learning about a country's background and history.

Kewi Kam, Tsuen Wan Public Ho Chuen Yiu Memorial College