Introduction to English as a Second Language Teacher’s Book

One of the earliest-known inventions is the bow and arrow, which is still used throughout the world today, 15,000 years     1     it was first invented. Of course, these days, the bow and arrow     2     (use) mainly in sporting events, but in some places it is still a means of killing animals for food.

In western Asia, another extremely important invention was born — the ability to produce pots. As long as 6500 years ago, people were producing pottery, mostly plain and without designs, but the technique has changed little since.

Some people say that the wheel is the single most important invention. Early examples from about 5000 years ago have been found in the forests of Europe. Around 1500 years later, the Phoenicians used sand, limestone and sodium carbonate to produce     3     else which we would be lost without-glass.

How many things do you lock with a key every day? Doors, cupboards? The car? We really don't think much about them,     4     we? Well, the first example of a lock and key dates back to 2750 years ago, in Assyria. This is a lock on a large wooden door in the palace of Sargon II.

Another amazing invention, which we probably take for granted these days, is the skill of knitting       5     first appeared in the Roman Empire, some 1700 years ago. The     6     (early) examples are knitted socks!

Eye glasses developed from just one lens in a frame, like a simple magnifying glass, way back in the 13th century. In about 1290, the idea to put two lenses in a frame to sit on the nose was developed in Florence. And, believe it or not, the modern contact lens is 120 years old! 

Time flies and we spend a lot of time     7     (check) how much time we have left! This would be impossible     8     clocks and watches,     9     are all around us: on walls, on our wrists, on our PCs, and even on our mobiles and iPod’s. The first pocket watch was invented by Thomas Tompion (1639-1714) in England 330 years ago, and his watch — face design, with two (and sometimes three) hands moving around a single dial,     10     (remain) largely unchanged in all that time.

Are energy drinks safe? In spite of       1     known dangers of energy drinks, the market for them is booming. The Global Energy Drink market is expected     2     (reach)$72 billion by 2024. This is great news for energy drink manufacturers, but what are     3    (consumer)really getting when they buy these drinks?

Energy drinks can cause dehydration( 脱水). The main source of energy in most energy products is caffeine. It can be     4    (particular)harmful for people who drink these products     5       the first time and don’t compensate with extra water, says nutritionist Beth Warren.

Energy drinks can increase heart rate. Caffeine also     6    (contain)a heart rate risk, says nutritionist Lisa Cohn,     7       found that energy drink abuse among teens caused increased risk of heart attack, especially in those with potential heart conditions.

Energy drinks can damage teeth. Energy drink products contain citric acid( 柠檬酸), which does harm to teeth. A study     8    (compare)sports drinks and energy drinks found that energy products have significantly       9    (high)acidity and greater capacity to dissolve enamel( 牙 釉 质 )compared to sports drinks. In fact, the     10    (lose)of enamel after exposure to energy drinks was more than twice higher than after exposure to sports drinks.

Known as the “father of hybrid rice”, Yuan Longping considers     1    (he) a farmer because he continually works the land in his research. He looks like    2    (million) of Chinese farmers, for     3    he has struggled for years. Born in 1930 in Beijing, Dr Yuan graduated from Southwest Agricultural College in 1953. After     4    (graduate), he worked as a researcher. He realized that larger fields were not the solution     5    food shortage. Instead, farmers needed to boost yields in the fields they had. Through intense effort, Yuan got over enormous technical     6    (difficulty) and developed the first hybrid rice in 1974, which enabled farmers    7    (expand) their output greatly. Yuan’s rice has helped feed not just China, but many other countries that depend on rice as well. Yuan Longping cares little for wealth and fame. Instead, he     8    (make) large donations to support agricultural research.

    9    impresses people most about Yuan Longping is his ongoing ability     10    (realize) his dreams. Despite his advanced years, Yuan Longping is still young at heart and full of vision, and everyone is waiting to see what he will dream up next.