1 . Born in Potsdam (in the Kingdom of Prussia) in 1821, Helmholtz was one of the 19th century’s most knowledgeable scientists, whose name turns up in the histories of multiple scientific fields and specialties. As a youngster, he had an interest in physics, but that seemed a financially unwise career choice. He went to medical school and studied physiology instead, because he was drawn to others who promoted the point that physiology should be based on the principles of chemistry and physics, not the vital forces that had been popularly emphasized previously.

After earning his medical degree, Helmholtz served as an army surgeon before becoming professor of physiology at the University of Konigsberg. During that time, he composed a groundbreaking paper on the conservation of energy, which made him a good reputation in science community. His main argument is that all science can be reduced to mechanics. It is emphasized that Newtonian mechanics and Lagrangian mechanics are mathematically equivalent, so a force can be measured by the Laplace method in terms of the energy transferred by the force or the work done by the force. All of this energy is conserved. While at Konigsberg, he studied the nervous system, optics (光学) and acoustics (声学),especially with regard to the physiology of the senses. Then he moved on to the University of bonn as professor of anatomy (解剖学) and physiology.

After some time at the University of Heidelberg, where he became interested in philosophy, in 1871 he was awarded the physics chair at the University of Berlin. At last he could focus on physics, emphasizing the importance of the principle of least action for explaining physical phenomena. He also explored the branches of Maxwell’s new theory. By this time, he was recognized as one of Germany’s premier scientists, until his death in 1894.

3 . Throughout history, great cities have risen and fallen. Some of them are seemingly lost in time — until artifacts (古物) are discovered that bring them back to life.

Teotihuacán

Located outside of Mexico City, Teotihuacán is thought to have been settled around 400 BC. By 400 AD, it was the most influential, powerful city in its region. Teotihuacán’s real treasure is its massive step pyramids. Much of the city’s history is still a mystery, but some believe that its decline came from changing climate conditions like long-term droughts.

Petra

This ancient city in southern Jordan flourished from the 4^th century BC to 106 AD. It was an important place for spice and silk trade routes. It also had a complicatedly-designed water management system. Petra was occupied by Rome in 106 AD, and the trade routes soon shifted. Hundreds of years later, earthquakes damaged the water system and Petra was abandoned.

Pompeii

Endless tales have been told about the tragedy of Pompeii, which occurred on August 24, in the year 79 AD, when the volcano Vesuvius erupted. The entire town was swiftly covered in ash and soil. Everything was frozen in time. The site was unearthed in the 18th century, and the evidence found provided a great detail of insight into daily living in this ancient Italian city.

Ctesiphon

Located about 20 miles outside of Baghdad, Ctesiphon was one of the greatest cities in Western Asia in the 6^th century. It was conquered (征服) by Rome, and then by the Byzantine Empire. In 637 AD, it was captured by the Muslims. Many believe that the ancient city was the inspiration for the city of Isbanir mentioned in the Thousand and One Nights folk tales.

4 . We have had bad news this week, my husband was laid off on Tuesday. _________, we are better off than most family, and still be able to _________ our finances until he finds another job.

When seeing doctors, nurses and staff working around the _________ to take care of patients during this COVID-19 pandemic, my husband gave me $100 cash and said, “Go out, buy some restaurant gift cards and take them to the _________ for the medical workers.” Restaurant gift cards can make it _________ for them to quickly get meals between shifts. Without health care _________ we cannot join in that fight directly, but we can _________ them — with meals, with supplies and even with a _________, heartfelt “thank you”. I don’t often have to say we can’t do things because we _________ the money ourselves, but that was my first __________. Realizing my __________ he said, “We will be okay, we need to look outwards not inwards.” What a special man! I agreed that it was a __________ attitude to have! It was a beautiful thing to remain kind to __________ others even in our __________ moments. __________ thoughts helped us pull through smoothly. He found another job soon.

Always think positively, have 100% faith and success is yours.

6 . With the popularity of the Internet in recent years, major webcast platforms are in full swing, especially in this special period, many people are staying at home, crazy to engage in webcast. We should treat this problem in a dialectical way of thinking. Everything that is beneficial will have disadvantages. Today, with the rapid development of the Internet economy, “webcast” has become a means of information spreading. Today, with the popularity of webcast, we should comprehensively analyze its advantages and disadvantages.

“Webcast” has become a hot word, and even derived a series of new industries and new occupations, effectively promoting the development of social economy and the diversification of business forms. For example, in the stage of resumption of work and production after the epidemic was effectively controlled, the live broadcast of network anchors promoted the rapid growth of some regional economies to a certain extent. For example, CCTV invited live broadcast talents to combine with stars to carry out live broadcast in Wuhan and other areas with serious epidemic, which effectively and rapidly promoted the economic development of Wuhan at that time. At the same time, educational live broadcasting can make up for the gap between education in backward areas and advanced areas to a certain extent, give children equal opportunities to learn, promote the national plan of educational equity, and let more children see the outside world.

But webcast also brings many problems. First, the quality of live broadcast goods is uneven. Many live broadcasters push and sell the goods in a template manner without detailed understanding. After customers receive the goods, the goods are not the right board. Because of logistics express fees and other reasons, they are also too lazy to argue, resulting in a gradual decline in public praise. Second, while bringing joy and economic growth, the live broadcast of online celebrity has made the social atmosphere more impetuous. The children’s ideal has become “I want to be an online celebrity”, thinking that there is food by one face. These dregs need to be abandoned. Third, the supervision of webcast is not strict, and vulgar information often appears, which brings bad social atmosphere.

To this end, we should first strengthen the supervision of webcast from the institutional level, especially the examination and approval of live broadcast content, standardize all live broadcast platforms, increase punishment, curb the bad live broadcast atmosphere from the source, and set up relevant vocational skills training according to the situation; Secondly, all broadcasters should effectively choose the live broadcast content, conform to the mainstream social value orientation, ensure the quality and level of live broadcast, and gradually get out of the mindset of echoing others; Finally, all public opinion media should create a positive and sunny attitude at the social level, treat the new thing of “live broadcasting” correctly, and guide public opinion to the right track.

8 . Once upon a time, there was a farmer with foresight and wit. The story of his resourcefulness is still widely publicized. The most wonderful one is the story of how he once played tricks on the devil.

One day, the farmer worked in the field all day. When it was dark, he was preparing to go home. Suddenly, he found a pile of coal burning in his field. He was very surprised, so he went up to have a look and found a little black devil walking on the burning pile of coal. “Are you sitting on the treasure?” Asked the farmer. “It’s the treasure.” The devil replied, “and more than you’ve seen in your life!” “If the treasure is in my field, it belongs to me.” Said the farmer. “It’s yours!” The devil said, “as long as you are willing to give me half of the harvest in two years. I have plenty of money, but I prefer the fruit on the ground.” The farmer agreed to the deal and said, “in order to avoid disputes in our distribution, everything on the soil belongs to you and everything under the soil belongs to me.” The devil was satisfied, but the clever farmer planted carrots.

Now the harvest season has come, and the devil has come again, asking for his harvest. But he got nothing except those withered and yellow leaves; But the farmer was happily digging his radish. “You took advantage of it this time,” said the devil. “You can’t do it next time. The ground belongs to you and the underground belongs to me.” “Whatever you want.” The farmer replied. It’s time to sow again. This time, instead of sowing radishes, he planted wheat. When the wheat was ripe, he came to the field and cut the straw to the ground. The devil came again. Seeing that he got nothing except stubble, he turned around and walked along the stone crack. “That’s how I tricked the devil.” With that, the farmer quickly picked up the treasure and went home.

9 . Mathematics is becoming more and more important in today’s society, but more and more people find themselves unable to learn mathematics. Here are some suggestions for learning mathematics:

Preview in advance

Preview in advance can have a general understanding and grasp of what the teacher says in class, grasp the key points when listening to the class, and focus on the key and difficult points that you won’t be able to hear. However, mathematics textbooks are more obscure and difficult to understand. If you only rely on self-study, it is often difficult to look down and learn. Therefore, it is important to grasp the classroom and follow the rhythm of the teacher in class.

Listen carefully

The concept of fixed classrooms in some middle schools is weak, so the place and seats of classes are moving, and classes are basically held in relatively large ladder classrooms. The classroom space is relatively large. It is recommended that you sit in front, which can hear the teacher’s lecture more clearly, facilitate interaction with the teacher, and also enable you to concentrate on avoiding missing knowledge points due to distraction.

Review in time

A lot of knowledge about mathematics is connected. We need to review and summarize the knowledge we have learned so that we can master it. Of course, some students don’t have enough patience to review, but they also have to review what they learned in the previous class every day. Review also has to concentrate, must be of high quality, high efficiency, and do not procrastinate.

Mastery

The knowledge of mathematics is advanced layer by layer. The knowledge of the next chapter is closely connected with that of the previous chapter, which requires students to study steadily, step by step, and master key knowledge. They must not learn in a hurry. In this way, they can not connect knowledge, but also disrupt the pace of learning and increase the difficulty of learning.

10 . One evening, I was on a train going home. I had worked all day and was ________. A woman with two little children came and the older girl ________ the seat beside me.

She fell asleep soon. Her head rested on my ________. I stared at her, judging the mom. Why were her kids up so late? When we arrived, both children were asleep. I _______ to help carry her babies. When we ________ at the deserted station, I ________ her panic. It was dark and late.

Having a car parked nearby, I offered to give her a ________ . She hesitated. I ________ understood her hesitation. I reassured her I didn’t mind. On the way we sat in silence. The breathing from her sleeping babies was the only ________. As we neared our destination, she said, “ I am ________ you were here. ”

I pulled into a dark alleyway (小巷). A row of ordinary townhouses appeared. I had driven by countless times but never realized the haven (避难所) they ________. I reached to unbuckle (解开) my seat-belt, but she ________ me. “ You can’t come in. We aren’t ________ to tell anyone where these houses are. ”

She woke her children, thanked me and left. People are put in our ________ to influence us. This woman showed me her love for her children. She helped me remember to be thankful and ________ me of the importance of kindness.