China has the     1     (large) network of high-speed railways in the world. As of 2022 it encompassed(包含) over 40, 000 kilometres (25, 000 miles) of high-speed rail or over two-thirds     2     the world’s total. It is also the world’s busiest with an annual ridership of over 1.44 billion in 2016     3     2.01 billion in 2018 more than 60% of total passenger rail volume. By the end of 2018, the cumulative(累计的)number of passengers     4     (deliver) by high-speed railway trains was reported     5     (be)over 9 billion. According to Railway Gazette International, select trains from Beijing South to Nanjing South on the Beijing-Shanghai high-speed railway have the highest average operating speed at 317. 7 km/h as of July 2019.

The improved     6     (mobile)and interconnectivity created by these new high-speed rail lines have generated     7     entirely new high-speed commuter(通勤者)market around some urban     8     (area). For example, commutes via(通过) high-speed rail between Beijing and     9     (surround) cities have become     10     (increase)common.

4 . A woman who has struggled to come to terms with her alopecia (脱发) since she was a teenager is now working as a ______.

“I first noticed it when I was standing in the mirror trying to ______ my hair in a ponytail (马尾辫) and saw a small patch with no ______ close to my forehead,” Hansson, 26, said, “I was young at the time so I was mostly ______ that it was cancer since that’s ______ the first thing you think of when you see hair loss.”

After her diagnosis, only Hansson’s closest friends and ______ knew about her condition as she tried to keep it a secret and ______ that she became “good at hiding it”. However, as she got older, Hansson learned to accept her aesthetic (美感) and says that she is now ______ going out in public without wearing a wig. In fact, she has even ______ a career in modelling, “Now I feel like I can be ______ and that I don’t need to ______ it anymore,” she explains.

Hansson ______ not accepting her alopecia sooner, and she says that she is now happy doing what she loves and ______ other sufferers to do the same. “Don’t hide,” she said. “It will only make you feel ______. A big stone of suffering will ______ your body if you can just be yourself.”

5 . 3D-Printed Violins

While professional violinists often have instruments that cost between $2000 and $10, 000, it is possible to have one that costs millions depending on how they were and who made them.     1     This can make it hard for many to access the instrument, especially for beginners and music classrooms.

However, the good news for them is that they will meet with low-cost and durable (耐用的) 3D-printed violins thanks to The Acoustical Society of America’s AVIVA Young Artists Program. The team’s inspiration roots in multiple places. Their goals were to explore the new world of sounds created by using new materials, to use the new technology of other fields, and to make music education accessible through the printing of more durable instruments.     2     The method of distribution has yet to be decided — it could involve shipping fully printed violins, sharing the 3D-printing files with makers, or a combination of both.

    3     The neck and fingerboard are printed in smooth ABS plastic to provide a comfortable grasp for the musicians, while the violin’s body is made of a plastic polymer substance, much like a typical acoustic (原声的) violin. The outcome is a violin that sounds darker and softer than traditionally built violins.     4    

“The next step is to lower the costs of production for making such instruments more widely available, especially in the field of education,” said Mary-Elizabeth Brown, director of the AVIVA Young Artists Program. Violins are not the only instruments that are produced through 3D-printing technology.     5     Effective results have been obtained from many of them.

6 . Prehistoric people may have used firelight to create the illusion (错觉) of movement in their art. An analysis of 50 carved stones dug out in France suggests that when the stones were placed near a fire, the light made the carved animals seem to move, researchers report April 20 in PLOS ONE. These stones, or “plaquettes” ware found in the 1860s in a rock-shelter called Montastruc, and are carved with animals such as horses and deer. The site was used by Magdalenian people, hunter-gatherers who inhabited (居住) the area between 23, 000 and14, 000 years ago.

The researchers analyzed heat damage on the stones, which indicated them being directly exposed to high temperatures for a long period, and created 3-D models of the stones. Those models were imported to a virtual reality software   where they were placed next to a virtual hearth (壁炉炉床) so that the areas of heat damage were closest to the flames, mimicking (模拟) how the stones might have been placed in real life. The researchers then observed the visual effects of the virtual reality light.

It was surprising to see how dynamic the art was and “how changed your experience of the art was by a simple thing, just putting it close to a fire,” says Andy Needham, an archaeologist at the University of York in England. The work suggests that the artists purposely carved along the outline of the rock to influence viewers to see meaningful movement through the random pattern of firelight, he says.

The finding adds to archaeologists’ understandings of the relationship between early people’s artwork and fire. Another recent study found that Stone Age humans created “hidden” art in dark caves which could be lighted and made visible only with the help of the right lighting.