1 . Semiconductors or chips are essential components in things we use every day. They’re made from the material that gave Silicon Valley its name. And they handle everything from artificial intelligence processing to simple functions like translating the press of a button into an electronic signal. Think of them as the brain of a device. So, what has happened recently？

When the pandemic shut down car factories in March, automakers made a prognosis that there would be fewer orders for passenger vehicles, so in turn cut down their orders for chips. At the same time, working from home and 5G drove demand for laptops, smartphones, cloud services and data centers. So those industries increased their orders for chips. That caused chip makers to switch production to those areas rather than pile up chips they couldn’t sell. But what both car and computer companies didn’t expect was a quick rebound(反弹)in demand for their products.

So here lies the problem. There’s now not enough supply to meet demand and building chip factories takes years and costs bilions of dollars. How bad could it get? Chip shortages are expected to wipe out 61 billion dollars of sales for automakers alone. And big chip makers like Qualcomm, NXP and Infineon say the auto industry isn’t the only sector to get hurt. Games console makers say things will get worse before they get better, potentially impacting holiday sales.

President Biden has signed an executive order to look into why the US is so dependent on overseas chip manufacturers, like Taiwan’s TSMC and South Korea’s Samsung. So how long before supply meets up with demand? Well, it’s a guessing game. But some analysts say we won’t see signs of a turnaround until the second half of the year.

2 . Nowadays, you’ll have a hard time finding a major bank, a big accounting firm, a promising software company or a government that did not research cryptocurrencies(加密货币), publish a paper about it or start a so-called blockchain project.

In simple terms, a cryptocurrency is a digitized currency spread through multiple computers in a shared network. The decentralized(分散的)nature of this network keeps them from any control from government regulatory bodies. Cryptocurrencies can be sent directly between two parties via the use of private and public keys. These transfers can be done with minimal processing fees, allowing users to avoid the expensive fees charged by traditional financial institutions.

A cryptocurrency like Bitcoin consists of a network of peers. Every peer has a record of the completehistory of all transactions(交易)and thus of the balance of every account. A transaction is a file that says, “Bob gives X Bitcoin to Alice” and is signed by Bob’s private key. It’s basic public key cryptography, nothing special at all. After signed, a transaction is conducted in the network, sent from one peer to every other peer.

Cryptocurrency has the following advantages and disadvantages:

Funds transfer between two parties will be easy without the need of the third party like credit cards or banks, so it is a cheaper choice compared to other online transactions. Payments are safe and secured since cryptocurrency systems come with a user “wallet” or account address which is accessible only by a public key and private key. The private key is only known to the owner of the wallet. The almost hidden nature of cryptocurrency transactions makes them easy to be the focus of illegal activities.

Cryptocurrencies are not accepted everywhere and have limited value elsewhere. There is concern that cryptocurrencies like Bitcoin are not rooted in any material goods. Some research has identified that the cost of producing a Bitcoin, which requires an increasingly large amount of energy, is directly related to its market price.

3 . Among the countless natural landscape in China, waterfall is one of the most beautiful wonders. Visiting these waterfalls will bring the chance to view some of the most striking sights in China just like Americans do in Niagara Falls.

Hukou Waterfall

Best Time: April~May, September~November

Recommended Visiting Time: 2～3 hours

When the Yellow River flows to Hukou Village where the width of the river course is shapely narrowing to 20～30 meters from 500 meters, the water pours into the lower riverbed and forming the Hukou Waterfall. It is a magic wonder mounted on the Yellow River, giving tourists a heart-shaking sight and stimulating your boundless imagination. It is the largest yellowish waterfall in the world and the China's second largest waterfall.

Because the Hukou Waterfall is located in a joint of Shanxi and Shaanxi, you can visit it from Shanxi side or Shaanxi side. Generally, visiting it from Shanxi side allows you to see more other small attractions along the Yellow River.

Huangguoshu Waterfall

Best Time: June~October

Recommended Visiting Time: 3～4 hours

Huangguoshu Waterfall is the largest waterfall in China and the tallest Waterfall in the world. The Huangguoshu Waterfall pours from the over 70 meters high cliff and gives out huge noise, providing a great visual feast to the viewers. There are several places to enjoy a different view of the grand waterfall.

One is Water-Curtain Cave, which is hidden behind the waterfall. It is a 134-meter long with fantastic stalactites（钟乳石）. In the cave, you can also see many flying small springs.

Nuorilang Waterfall

Best Time: all the year around

Recommended Visiting Time: 1 hour

Located in picturesque Jiuzhaigou Valley, the Nuorilang Waterfall is an attractive waterfall. With a width of 270 meters and a height of 24.5 meters, it is the widest waterfall and one of the largestwaterfalls in China and the most photographed waterfall in Jiuzhaigou. The famed Chinese TV series Pilgrimage to the West has filmed there.