A sleep-deprived person cannot focus attention optimally and therefore cannot learn efficiently. Also, sleeping has a role in the consolidation of memory, which is essential for learning new information. Apart from giving them extra exercises and tutorial lessons, parents should consider whether their children have enough sleep.

In Hong Kong, schools, teachers, parents and therefore pupils focus mostly on academic scores. It can either bring effective motivation, or add dangerous stress. Life for our students shouldn’t be all about results. How about health and dreams?

Cindy Lem, Yau Yat Chuen

Zoo needs an upgrade, not closure

There have been calls to shut down the Hong Kong Zoological and Botanical Gardens if the government fails to improve the substandard living environment in the park.

Undoubtedly, the present living conditions in the park are not up to standard and affect the quality of life of the animals. There is insufficient heating to maintain comfortable temperatures during winter, while the cages are too small and cannot support the activities of animals.

These are not the only problems found in the zoo, and ­reflect the fact that the facilities in the park should be upgraded to improve the animals’ quality of life – and give them some ­dignity. A responsible government would never shirk from making the park a ­better place to live for the 300-plus animals.

Despite the understandable frustration of animal welfare groups about delays in ­remedying the problems, we can’t just shut the zoo down. What happens to the animals then? Many would not survive relocation or release back to the wild.

The zoo is also a very special place for Hongkongers. It’s the only one we have, it’s free to get in and we can’t see such a range of animals, or rare ones, at Ocean Park, where admission is too expensive for many.

Our zoo has an educational value and is a good place to relax. It shouldn’t be closed because of government inaction.

Grace Lok, Fo Tan

Low profiles the secret for PR officials

With reference to Alex Lo’s ­column (“Spin doctors: no value for a lot of money”, April 2) it’s not so much the “a lot of money” that bothers this concerned ­citizen, for the government’s PR people probably paid a lot less than their Singapore counterparts, including their ­expenses.

What bothers me is that they are such obscure plodders you hardly know they are there.

You send them a suggestion, they adhere to the office-practice rule, to send you an automatic computer-generated acknowledgement exactly 10 days later, even if it’s on a matter as urgent as the 79-day “Occupy Central”.

When they do initiate action to come to you for advice, they would usually leave that advice to languish in the “too difficult” tray, leaving you in a lurch.

They should realise that if the solution could be easily found, they would not be paid so handsomely, would they?

Unlike the PR people during the colonial period, they hardly fought back against unfair ­adverse criticism generated by the opposition, so much so it­ became tacit acknowledgement of the criticism.

These highly paid and apparently underworked officials should learn from Singapore: tell the opposition they should not criticise unless they have a constructive alternative to offer.

Peter Lok, Chai Wan

Green lean is undermining progress

Desperately poor people focus on feeding their family and have no spare energy to support secondary concerns such as the environment.

Destitute societies also see large families as free labour and old-age insurance. Thus poverty inevitably produces growing populations and environmental degradation.

The industrial revolution, powered by abundant reliable energy from coal, oil and gas, provided rural labourers with better-paying jobs in industry and government. With kerosene tractors, iron ploughs and no draught horses to feed, farmers had more food to sell. Food ­prices fell, cities grew, and ­society supported more culture, conservation and welfare.

With increasing prosperity Western families became ­smaller, reducing birth-rates ­below replacement levels thus moderating population pressure on the environment.

Today’s green policies are reversing these centuries of progress. They are restricting ­mining, farming, forestry, ­fishing and heavy industry by delaying approvals, denying ­access to land, increasing taxes and the welfare payments, and making electricity more costly and unreliable. These policies destroy industry, savings and jobs. Chronic unemployment undermines the ability to ­support arts, environment, ­welfare and overseas aid. Green charities will also suffer.

Viv Forbes, Rosewood, Queensland, Australia

Disneyland in Shanghai no threat to HK’s

Shanghai Disneyland is opening in mid-June, and its tickets have already been sold out for the first three operating days but Hong Kong’s Disneyland should not feel threatened.

Our theme park is a success now and is already actively ­luring visitors from various countries, and not just targeting the mainland. By using this method to stabilise attendance at the park, the overall number of visitors will not be greatly ­affected if more mainlanders choose to visit Shanghai Disneyland instead of Hong Kong.

Hongkongers may even be more inclined to visit their own Disneyland if fewer mainlanders turn up.

Lois Ng Kam-yuet, Yau Yat Chuen

Change eating habits to save threatened fish

I refer to the report (“Endangered wrasse ‘sold illegally’ ”, March 18).

One way to prevent the humphead wrasse from becoming extinct is to change ­people’s eating habits by raising the price through increased ­taxes on the traders. Fewer ­people will eat it, and traders won’t buy from the fishermen.

The government must raise public awareness also and schools should educate students to avoid eating this kind of endangered species. Introducing other kinds of cheaper fish that also taste as good will help humphead stocks recover.

If people have a higher awareness and act responsibly, not to kill and trade in endangered animals, the whole ecosystem and our environment will be beneficiaries.

That means fewer animals will become extinct.

Carman Ng Ka-man, Kowloon Tong