In photosynthesis, trees absorb carbon dioxide and release oxygen to the atmosphere. They help maintain the cycle of life.

If there were no trees, people would not exist anymore.

We should be environment-friendly and join green activities, such as Harbour Day.

CHAN CHUNG-HIN

The Chinese Foundation Secondary School

Thanks for your letter, Chung-hin. I'm happy to hear that you are taking an interest in environmental issues. Trees are indeed wonderful - in addition to the great job that they do release oxygen into the air, they also have a very calming effect on people.

A walk or run through the country park is so much more relaxing than a run in the gym for this very reason. The combined effect of all the trees - all the greenery - is very relaxing.

I have a favourite tree that I can see from my living room. It's in the centre of the courtyard of what used to be Victoria Prison. The government is still deciding what will be done with the land, but if they try and do anything to that wonderful, old tree I will definitely speak out.

Kate, Editor