Invented in the Tang Dynasty and widely adopted after the Song Dynasty in Fujian, the watertight-bulkhead(水密舱壁) technology permits the construction of ocean-going ships with watertight compartments(隔层). If one or two cabins are accidentally damaged at sea, water will not flood the other cabins and the ships will remain afloat.

The experience and working methods of watertight-bulkhead technology are transmitted orally from master to apprentices. However, the need for Chinese junks(中国式帆船) has decreased sharply as wooden ships have been replaced by steel-hulled ships, and today only three masters can claim full command of this technology. Associated building costs have also increased owing to a shortage in raw materials. Therefore, the inheritance(继承) of this heritage is decreasing, and inheritors are forced to seek alternative employment.

Zhang Guohui, a 77-year-old inheritor of the watertight-bulkhead techniques used to make Chinese junks, has been making ships for more than six decades. Coming from a poor family in a fishing town in East China's Fujian Province, Zhang started to make a living at the age of 16fishing on the open seas, which is where he developed a keen interest in constructing boats. As a fast learner, Zhang was later sent to shipyards in the cities of Quanzhou and Xiamen in Fujian Province, where he received training and became a master of traditional Chinese junks and gained fame because of his extremely skilled craftsmanship in the construction of these junks.

In fear that the traditional skills would die someday, Zhang started to restore old ships and make model junks for the museum with his 20 years of shipbuilding skills. "The restored ancient ships are the historical witnesses of Quanzhou as a maritime center of the East and Southeast Asiatrade network," said Zhang, adding that he finds the work meaningful since younger generations can learn from exhibitions of ancient ships that their ancestors had advanced shipbuilding technology at an early stage of development. "As long as I'm alive, I'll keep passing on the heritage," he said.

As the second largest city of the Republic of Korea, Busan draws global attention. Here are some routes for visıtors to have fun.

The First Route

Start off at the Haeundae Beach, where you can take a walk, sip a coffee, or try local fish cakes before heading up to BUSAN X the SKY. This observatory occupies the top floors of the city's highest structure, where you'll be attracted by the wonderful urban views. You can also visit the old Haedong Yonggunsa Temple along the route.

The Second Route

With its popular Songdo Cable Car moving quickly over the water to a park, this route offers amazing views of the city's traditional core. It's just a quick taxi to the Yeongdo Island, home to some of Busan's oldest neighborhoods, including the Huinnyeoul Culture Village. Overlooking the water, the whole picture that you can see is arguably the most romantic scene.

The Third Route

As a port city, you should head to the old harbor district of Nampo-dong to find its real charm. This is where you'll find the Jagalchi Market, the open-air seafood market that's not only a strong wave to the senses but also the city's living and beating heart. Walk along its gathering as you see fresh seafood from the sea, along with the vendors（摊贩）who sell it all.

The Fourth Route

Shinsegae Centum City is not far from the Gwangalli Beach, a crowded area of sand, cafes, and eateries looking out across the water to the Gwangan Bridge. There will be a cool drone（无人机）show on Saturday in the evening of a hot summer and a fireworks festival in November. For a unique experience, book a sunset stand up paddle boarding（SUP）trip to the bridge back with professional surfers.

We have a family tradition where each year, on New Year's Eve, we sit down and go through old albums. This year, when we were doing this annual routine, I noticed my grandmother looked shorter now than in pictures from when she was younger.

Our height decreases with age. The height that most of us boosts during our teens and twenties suddenly decides to leave us behind as we get increasingly older. So we se our parents and grandparents "shrinking".

This loss in height is observed in both males and females and across continents. Aging is universal; so too is our gradual reduction in height. People typically begin losing their height around the age of 30 years. Every ten years after this age, humans lose almost one centimeter, which roughly translates to about one half of an inch. This decrease in height also accelerates with age. Men and women lose height differently. Women lose more inches compared to males of the same age. Also, interestingly enough, the rate of height loss depends on their initial height, with the taller ones losing more height.

The length of leg bones and the spine（脊柱）determine the height of a person. These normally attain their maximum length by the end of adolescence, after which one's height does not increase. During our "adult phase", the length of the leg bones remains pretty much the same, but the spinal bones tend to play a key role in the reduction of height. Besides, the ligaments（韧带）of the foot start degenerating with age. This arches our foot down. Thus, our height may reduce slightly. In addition, the body loses its lean mass muscle with age due to, in part, loss of muscle tissues. This condition is age-related loss of muscle. The muscle fibers shrink and are replaced at a slower rate. This muscle loss makes us look shorter.

Nothing can really push the stop button, but it can lose some speed through appropriate diet, regular exercise, and general avoidance of alcohol, tobacco, and caffeine.