IELTS Sentence Completion

 

The Invention of the Airplane

The invention of the airplane revolutionized human transportation and communication. While many inventors experimented with flying machines, it was the Wright brothers — Orville and Wilbur — who achieved the first successful powered flight in 1903 in Kitty Hawk, North Carolina. Their airplane stayed in the air for just 12 seconds, covering a distance of 37 meters, but it was a historic moment that changed travel forever.

The brothers had spent years studying the principles of aerodynamics and testing different designs. One of their most significant contributions was the invention of three-axis control, which allowed pilots to steer and maintain balance during flight.

After their first flight, aviation technology advanced rapidly. Airplanes became faster, safer, and capable of carrying more passengers. Today, air travel is a common mode of transport for millions of people around the world, connecting distant locations in just a few hours.

Despite its convenience, air travel has raised environmental concerns due to carbon emissions. As a result, engineers are now working on developing electric aircraft and more fuel-efficient engines to reduce pollution and make flying more sustainable in the future.

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Sentence Completion (Passage 1)

Complete the sentences below with NO MORE THAN TWO WORDS from the passage.

1. The Wright brothers’ first flight took place in ________.
2. Their invention of ________ control made flying safer and more stable.
3. Airplanes today can carry a large number of ________.
4. Air travel is being questioned because of environmental ________.
5. Engineers are developing electric planes to reduce ________.

The Discovery of Penicillin

The discovery of penicillin is considered one of the most important medical breakthroughs in history. In 1928, Scottish scientist Alexander Fleming was conducting experiments with bacteria when he noticed that a mold, later identified as Penicillium notatum, had killed bacteria in one of his petri dishes. This accidental discovery led to the development of the world’s first antibiotic.

At first, Fleming struggled to isolate and produce penicillin in large quantities. It wasn’t until the early 1940s that a team of scientists in the United States and the United Kingdom managed to mass-produce the drug. During World War II, penicillin was used to treat infections in wounded soldiers and saved countless lives.

Today, penicillin and other antibiotics are used to treat a variety of bacterial infections. However, overuse of antibiotics has become a major concern, leading to the development of antibiotic-resistant bacteria. Doctors now emphasize the importance of using antibiotics only when necessary to help prevent resistance.

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Sentence Completion (Passage 1)

Complete the sentences below with NO MORE THAN TWO WORDS from the passage.

1. Fleming discovered penicillin while working with ________.
2. The mold that produced penicillin was called ________.
3. The large-scale production of penicillin began in the early ________.
4. Penicillin was first widely used during ________.
5. Overuse of antibiotics can lead to ________ bacteria.

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Answers (Passage 1):

1. bacteria
2. Penicillium notatum
3. 1940s
4. World War II
5. resistant

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Passage 2: The Importance of Rainforests

Rainforests are vital to the health of the planet. Covering only about 6% of the Earth's surface, they are home to more than half of the world’s plant and animal species. These forests play a key role in maintaining the global climate by absorbing carbon dioxide and producing oxygen.

In addition to their environmental role, rainforests provide resources for humans, including food, medicine, and materials for building. Many life-saving drugs have been developed from plants found in tropical rainforests. However, these forests are under threat from deforestation, caused by logging, agriculture, and mining activities.

Deforestation not only destroys habitats but also contributes to climate change by releasing stored carbon into the atmosphere. Conservation efforts are being made to protect rainforests, but more international cooperation is needed to ensure their survival for future generations.

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Sentence Completion (Passage 2)

Complete the sentences below with NO MORE THAN TWO WORDS from the passage.

1. Rainforests cover about ________ of the Earth’s surface.
2. These forests help regulate the climate by absorbing ________.
3. Plants in rainforests are used to make life-saving ________.
4. One cause of deforestation is ________.
5. Conservation of rainforests requires global ________.

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Answers (Passage 2):

1. 6%
2. carbon dioxide
3. drugs
4. agriculture
5. cooperation

 

 

Passage 1: The Origins of Chocolate

Chocolate has been enjoyed for thousands of years. The earliest evidence of chocolate consumption dates back to ancient Mesoamerican civilizations such as the Mayans and the Aztecs. They consumed chocolate in the form of a bitter drink, often mixed with spices.

When Spanish explorers arrived in the Americas, they brought cacao beans back to Europe, where sugar was added to sweeten the drink. Over time, the process of making chocolate evolved, and by the 19th century, solid chocolate bars were being produced.

Today, chocolate is enjoyed all over the world in many forms, from hot drinks to candies and desserts. However, the production of cacao remains labor-intensive, and much of it is grown on small farms in tropical regions.

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Sentence Completion (Passage 1)

Complete the sentences below with NO MORE THAN TWO WORDS from the passage.

1. The Mayans and Aztecs consumed chocolate as a ________.
2. In Europe, sugar was added to make chocolate more ________.
3. The first solid chocolate bars were made in the ________ century.
4. Cacao is mostly grown on ________ farms.

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Answers (Passage 1):

1. bitter drink
2. sweet
3. 19th
4. small

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Passage 2: The Great Wall of China

The Great Wall of China is one of the most remarkable architectural feats in human history. Built to protect China from invasions, the wall stretches over 21,000 kilometers. Construction began in the 7th century BC and continued for centuries, with different dynasties adding to the structure.

The wall was not only a military defense system but also served as a symbol of China’s strength and unity. Today, it is a UNESCO World Heritage site and attracts millions of tourists every year.

Unfortunately, some parts of the wall have been damaged by natural erosion and human activities, prompting restoration efforts to preserve this iconic monument.

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Sentence Completion (Passage 2)

Complete the sentences below with NO MORE THAN TWO WORDS from the passage.

1. The Great Wall was originally built to stop ________.
2. Different dynasties worked on the wall over many ________.
3. The Great Wall is considered a symbol of China’s strength and ________.
4. The wall is currently undergoing ________ efforts.

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Answers (Passage 2):

1. invasions
2. centuries
3. unity
4. restoration

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Passage 3: Renewable Energy in Iceland

Iceland is one of the few countries in the world that produces almost all of its energy from renewable sources. The country takes advantage of its abundant geothermal activity and hydropower to meet energy needs.

Geothermal energy comes from the heat beneath the Earth’s surface and is used to heat homes and produce electricity. Hydropower, on the other hand, uses moving water to generate power. These sources allow Iceland to have some of the cleanest energy in the world.

The success of Iceland’s energy system has attracted interest from other countries looking to reduce their dependence on fossil fuels.

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Sentence Completion (Passage 3)

Complete the sentences below with NO MORE THAN TWO WORDS from the passage.

1. Almost all of Iceland’s energy comes from ________ sources.
2. Geothermal energy uses heat from beneath the ________.
3. Hydropower is generated by ________ water.
4. Iceland’s clean energy system attracts ________ from other countries.

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Answers (Passage 3):

1. renewable
2. Earth’s surface
3. moving
4. interest

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Passage 4: The Life Cycle of a Butterfly

Butterflies undergo a complete metamorphosis, moving through four stages: egg, larva, pupa, and adult. The first stage begins when the butterfly lays eggs on a leaf. These eggs hatch into larvae, known as caterpillars, which eat leaves to gain energy for growth.

Once the caterpillar has grown enough, it forms a pupa, or chrysalis, in which it undergoes transformation. Inside the chrysalis, the caterpillar’s body changes completely, and after a few weeks, an adult butterfly emerges.

Butterflies play an important role in ecosystems as pollinators, helping plants reproduce and supporting biodiversity.

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Sentence Completion (Passage 4)

Complete the sentences below with NO MORE THAN TWO WORDS from the passage.

1. A butterfly begins life as an ________.
2. The larva stage is also known as a ________.
3. The pupa is sometimes called a ________.
4. Butterflies assist in plant reproduction by acting as ________.

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Answers (Passage 4):

1. egg
2. caterpillar
3. chrysalis
4. pollinators