Act now to save the planet
Greenhouse gases such as carbon dioxide make the earth warmer by trapping energy in the atmosphere. Global warming is a serious problem which could lead to changes in rainfall patterns and a rise in sea levels, making a huge impact on plants, wildlife and humans.
When scientists talk about climate change, they are mainly concerned about human activities such as the burning of fossil fuels and deforestation.
Already the polar ice is melting and we have seen extreme weather conditions, such as floods and typhoons, affecting many countries around the world.
We need to take steps to protect the environment before it is too late.
Bisha Gnawali, Delia Memorial School (Hip Wo)
Drawbacks outweigh the benefits
The public is divided over the Guangzhou-Shenzhen-Hong Kong Express Rail Link. I oppose the project because, at HK$66.9 billion, it is too costly.
The government says the railway can help boost Hong Kong's economy and start making profits after about 50 years.
But local officials could be wrong, as they have been with the Airport Express. The number of passengers taking this railway has fallen over the past few years because they prefer to use cheaper transport.
But the MTR Corp cannot reduce ticket prices because of the high cost of building the express.
I don't think the government should waste taxpayers' money on the proposed rail link to the mainland.
Also, authorities cannot force Tsoi Yuen villagers to leave their homes to make way for the railway. Their ancestors have lived there for hundreds of years and the village cannot be simply destroyed.
Although the villagers will receive a big amount as compensation, money is not everything.
The building of the rail link will also destroy the natural environment in Hong Kong and worsen its pollution problems. Hundreds of trees will have to be cut down and construction work will produce air and noise pollution.
The government should not go ahead with this project because the drawbacks outweigh the benefits.
Wan Wing-ki, Our Lady of the Rosary College
CityU's drug-testing breakthrough
A team of City University researchers have developed a method which uses acrylic resin - a type of plastic - to test blood, hair or saliva samples. They say this method could make drug tests cheaper, quicker and more reliable.
This is a very useful discovery, especially with the government conducting voluntary drug-test trials in Tai Po schools.
The government could use this technology which gives a result within one minute and requires little skill to operate.
The present procedure is too complicated, so the new plastic device may provide the answer.
Pang Pei-yan, Pooi To Middle School
I took part in an English solo speaking competition recently. Although I lost, I received a lot of encouragement from my friends.
My friends are truly wonderful - when I feel down, they cheer me up. When I am happy, they share the joy with me. I want to say 'thank you' to all my friends.
Samantha Lau Pui-ching, Fung Kai Liu Man Shek Tong Secondary School
Sport, whether it is swimming, basketball, table tennis, volleyball or badminton, is good for you.
It can help boost your physical and mental strength.
Make sports one of your hobbies and stay fit and healthy.