1 . Three Chinese astronauts from the Shenzhou-13 manned spaceship returned to the Earth after completing their six-month mission. One of their major goals was to prepare the station for future groups of taikonauts（中国航天员）who will complete theassemblyof the space station.

Thanks to a new quick return procedure carried out for the first time, Shenzhou-13’s return trip lasted about nine hours rather than the 24-hour trip for Shenzhou-12, with the return capsule only circling the Earth five times before entering its final return orbit instead of 11 times as in past missions.

The Shenzhou-13 crew was responsible for taking out some of the science instruments to be used for experiments on the station. They also performed two spacewalks, conducted more than 20 different science experiments in addition to delivering two live educational lectures.

Taikonaut Wang Yaping, who gave the first public class from the Tiangong-1 space station, gave two such classes on this trip to Tiangong-2, which were viewed by millions of school children in China.

In addition, the taikonauts were sent questions from 20 schools in 13 U.S. states by American school children. The pre-recorded questions and responses were shared with students, parents and teachers at a “My Questions to Taikonauts” event on April 9 sponsored by the Chinese Embassy in Washington, D.C.

This was the first six-month mission, which will give those on the ground the opportunity to study the effects of the longer duration mission on the taikonauts, especially on the ageing process. The six-month stay will be common for astronauts in the future.

Visiting the Wenchang Space Launch Center on April 15, Chinese President Xi Jinping said that the facility serves China’s new-generation, heavy-lift carrier（运载）rockets and plays a significant role in the country’s deep-space exploration. The Chinese President called for efforts to achieve “world-leading standards” for China’s spacecraft launch facilities.

7 . Chinese is mainly divided into 13 dialects（方言）and these dialects can be further divided into many kinds of local dialects. Putonghua (or Mandarin) the predominant dialect, is spoken by over 70% of the population and is one of the 6 official languages of the United Nations. Within these large dialect groups, there are small groups, many of which are difficult to understand. In Fujian, for example, people living 10 kilometres away from one another can be speaking different Min dialects.

Putonghua. It is the mother dialect of Chinese living in northern China and Sichuan Province. It is called Guoyu in some parts of China, like Hong Kong, Macao（澳门）and Taiwan. It is known in English as Mandarin Chinese, or Standard Chinese.

Wu. Spoken in Shanghai, most of Zhejiang and the southern parts of Jiangsu and Anhui. Wu is made up of hundreds of different of spoken forms.

Hakka/Kejia. Hakka is widely spoken in Fujian, Taiwan, and some countries in Southeast Asia.

Min. It is spoken in Fujian, Taiwan, and Southeast Asia. Min group is the most diverse（多样的）, with many different spoken forms used in neighbouring countries.

Yue. It is spoken in Guangdong, Hong Kong, Macao, Taiwan, all over Southeast Asia and by many Chinese living abroad.

Many scientists once believed that physical similarities between identical twins are genetic（基因的）, while their personalities, intelligence and other differences between them are an effect of their environment. Now scientists are discovering that the boundaries（界限）between genes and environment are not so clear.

Twins Jim Springer and Jim Lewis were adopted（领养）as babies and raised by different couples. When the Jims finally met at age 39, they discovered they had plenty in common. Both were six feet tall, 180 pounds. They had the same smile and the same voice. When scientist Thomas Bouchard Jr. invited the Jim twins to his lab, people there found it very hard to tell them apart.

But the similarities didn’t stop at the physical. They’d both had dogs named Toy. They had both married women named Linda and then their marriage broke up. They’d both been policemen, enjoyed music, and left love notes around the house for their wives. They had so much in common, it seemed unlikely these were just coincidences （巧合）.

The Jim twins were just one of 137 sets of separated twins. Bouchard tested. When they compared the twins’ IQ scores, Bouchard and his team reached a surprising conclusion（结论）. They concluded that intelligence was mostly connected to genes rather than to training or education. It seemed the differences in family and environment had little effect.

However, genes can’t control everything, argues geneticist Danielle Reed, who also studies twins. Reed’s research shows that though nothing can truly change our DNA, environmental differences that a child experiences before birth and in their first year can sometimes affect the way the DNA behaves, making even identical twins into very different people. “What I like to say is that Mother Nature writes some things in pencil and some things in pen,” She explains. “Things written in pen you can’t change. That’s DNA. But things written in pencil you can.”