It would be helpful to add a sequence of frequent low-power pings to assist with final localisation.

Intermittent pings and low-power pings may be harder to detect than continuous full-strength pings, but they are infinitely easier to find than no pings at all.

The tragic loss of MH370 is the second air crash in five years that has required a lengthy underwater search. The 2009 BEA Interim Report No 2 into Air France Flight 447 [which crashed into the Atlantic Ocean in June 2009] recommended that:

• Public aircrafts' underwater beacons should be improved to transmit for at least 90 days;

• Additional long-range underwater beacons should be mandatory; and

• We should consider making it compulsory for public airliners to regularly transmit basic flight parameters such as position, altitude, speed and heading.

Regrettably, almost nothing seems to have been done in the last five years, and little is planned for the future.

However, if the Chinese government was to require that all planes entering the country had long duration underwater beacons and regular flight data transmissions, it is likely that something would happen and fast. This example of Chinese leadership would be a fitting memorial to the passengers and crew of MH370.

I refer to the archaeological site discovered at an MTR construction site.

Relics dating back to the Song dynasty have been found at the site around To Kwa Wan station on the Sha Tin-Central link.

I think the MTR Corporation should realign this railway link so that the site can be preserved, because we know little of life in Hong Kong during the Song era.

It could help historians to fill in the blanks and learn more about this period of Hong Kong's history.

The MTR Corp should recognise the importance of this find and see its preservation as a priority, even if it means that the original route of the rail link has to be adjusted.

I would suggest that the government turns the site into an educational centre that students can visit and learn about their past.

There are few outdoor areas of historical importance in Hong Kong which students can go to.

Stephanie Ng, Kowloon Tong

I refer to the letter by Sandra MacDonald ("Seeking some answers on jury duty", April 15), and would like to provide some information on the jury system.

The constitution of the jury is governed by the Jury Ordinance (Chapter 3). Section 4 prescribes the qualifications for a juror while Section 5 sets out who can be exempt from the jury service (Note 1).

When considered eligible, a person's name will be included on the jury list.

When that person considers he/she is not eligible as a juror under Section 4 or belongs to the categories of persons who are exempted from jury service under Section 5, that individual should write to the registrar of the High Court within 14 days after the receipt of a notice of jury service to apply for exemption from jury service.

For each hearing day, the computer randomly picks a number of names from the jury list for summonses to be issued to those selected to attend court.

On receipt of the Summons to Juror, if there are reasons (for example, health, personal commitment and business engagement) rendering the summoned person unable to attend court, that person may apply in writing to the registrar of the High Court for excuse to attend on that occasion.

The registrar will consider evidence such as copy of itinerary and air ticket for overseas trip and medical certificate for health reasons.

Where the person involved is staying overseas, he/she must apply to the Immigration Department for the necessary immigration records in support of the application.

The registrar of the High Court will consider the application on its own merits.

If the registrar refuses an application, the summoned person has to attend court on that occasion but may still make the request for excuse to the trial judge when being selected by ballot as a juror.

For those who have been summoned to attend court (except those who have successfully applied for leave to be excused), normally they will not be required for jury service for a period of two years.

Those who remain on the jury list will stand to have an even chance of being randomly selected by the computer and be summoned to appear before the court to serve as jurors.

There are often articles and reports about obsessive parents who will do almost anything to get their children into a prestigious school.

They will often do this without thinking about what their children want and also whether such an institution is suitable.

Parents should be looking for the school that is suitable to the needs and abilities of their sons and daughters. Sometimes it might not be one that is particularly famous.

If they are forced into somewhere that they hate, then this could actually hurt them academically, as they may lose interest in the whole process of learning.

Children should not be overprotected. They need to learn to face and deal with problems on their own and to learn self-discipline.

There is a case in Hong Kong for educating parents with talks in schools.

The message should be got across to them on the need not to be overprotective and to let their children develop in a normal and natural way.

Full marks to Ken McGowan ("Zig-zag lines help protect pedestrians", May 5) for his letter.

Until reading it I thought that a police motorcycle patrol officer in Hung Hom and I were the only two people in Hong Kong who recognise the importance of these markings [near pedestrian crossings].

I saw this officer giving a ticket for the offence in Hung Hom a few years ago, but other officers not only fail to recognise it but frequently commit the offence themselves.

However, I am a little confused by Mr McGowan's quotation of Rule 191 of the UK's Highway Code as I recall that the word "parking" is irrelevant. In the UK, it is a driving offence to stop in the marked area (other than when stopping for pedestrians using the crossing, of course) which is why there are no yellow lines within these marked areas.

I suspect the law in Hong Kong is the same but, like so many others, is not being enforced.

The Transport Department and the police have ignored most of my letters regarding road safety for many years.

Perhaps, with luck, they will take some notice of Mr McGowan and start giving some constructive answers and, even better, take some decisive action.

The disappearance of prominent Chinese journalist Gao Yu has raised serious concerns for her safety ("Journalist fails to show up at commemoration", April 29).

Gao, an outspoken critic of the Tiananmen Square crackdown on June 4, 1989, had endured years of imprisonment because of so-called official outrage over her articles.

Despite the Chinese Communist Party's attempts to obfuscate the facts about its human-rights record, the "disappearances" of Chinese journalists and human-rights advocates is not all that uncommon.

What is disconcerting to friends of Gao is that the Communist Party is acting before the 25th anniversary of the Tiananmen Square crackdown on June 4.

Her disappearance clearly has political overtones.

Gao's case is further evidence of China's interminable repression of human rights.

The notion that its journalists, such as Gao, should be punished for speaking out on behalf of her fellow compatriots is hardly befitting of a country that purports to respect human rights.

That said, the international community would do well to recognise her accomplishments and demand her immediate release. She deserves no less.