Human beings have had its very first look at a black hole, thanks to pictures of the black hole from the Event Horizon Telescope (EHT). Now, the even 【小题1】(hard) work begins: figuring out 【小题2】it all means.

The pictures are the first evidence that the event horizon — the line at 【小题3】a black hole’s gravity is so strong that nothing, not even light, can escape —【小题4】(be) real. They show light from matter right next to the black hole bending around it to create a sort of bright circle, as 【小题5】(predict) by Albert Einstein.

However, even after the first pictures, many questions remain. The   biggest   is   how   general relativity (广义相对论), which governs gravity and the very large, 【小题6】quantum mechanics ( 量 子 力 学 ), which concerns the very small, fit together. We also don’t know where   【小题7】(exact) the light in the pictures comes from. Strictly   【小题8】(speak), the orange circle is actually a representation of colorless radio 【小题9】(frequent) photons (光子), rather than light.

The EHT is also trying to   take   a   picture   of Sagittarius   A*,   another   black   hole.   Unlike   the one pictured,     it   doesn’t seem 【小题10】(have) a jet, but it is interesting in other ways, particularly because we may be able to see it changing over time.

More people than ever pay for items with their mobile phones, whether they’re having their rewards card 【小题1】(scan) by a salesperson for the first time or they’ve gone “all in” by loading their Visa debit and credit card on their phone.

But as 【小题2】(rapid) as mobile payments have grown, the technology is still in its infancy. By 2025, many people could be leaving their wallets 【小题3】 and paying for almost everything using their mobile phones.

A survey discusses the 【小题4】(grow) of mobile payments since 1997 when vending machines that took payments by text 【小题5】(introduce) for the first time. Since 2010, the amount of money 【小题6】 has passed from consumers to merchants via smartphones 【小题7】(go) up nine-fold. By 2027, more than $721 billion will change hands via mobile one.

More importantly, though, more people and more merchants will feel 【小题8】(easy) to use mobile than before, whether it’s those NFC chips in your phones that let you hold your phone up to 【小题9】 scanner or via transaction apps. By 2030, Visa believes mobile payments could become the 【小题10】(prefer) method of both consumers and merchants.

After weeks of space travel, China’s Chang’e-5 lunar probe (月球探测器) was back on earth on Dec. 17th, 2020. It landed in Inner Mongolia in northern China with fresh samples (采样) from the moon. It’s reported that it’s China’s most challenging and 【小题1】(advance) space adventure. The project was divided into three periods: Circle, Land and Return. It ended 【小题2】(successful) early Thursday morning.

【小题3】 Thursday President Xi Jinping congratulated the complete success of the Chang’e-5 mission (任务)【小题4】 brought back the country's 【小题5】 (one) samples from the moon. Xi also offered warm 【小题6】(congratulation) and sincere greetings to all members who took part in the Chang’e-5 mission.

In 2018, China 【小题7】(plan) to send up the Chang’e-5 lunar probe. It was expected to realize lunar sample collection. On Nov. 28, 2020, it entered the lunar orbit completing an important step on 【小题8】(it) way to collect and return moon samples.

The Chang’e-5 mission has achieved the extraterrestrial (外星球的) sampling and returning for the first time. It is another major achievement in overcoming difficulties by 【小题9】(give) full play to the advantages of the new nationwide system, marking 【小题10】 great step forward in China’s space industry. This will contribute to deepening the understanding of the birth of the moon and the evolution history of the solar system.