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Life-Changing Science Discoveries
Here's a look at some discoveries that have changed the world. It's impossible to rank their importance, so they're listed in the order they were discovered.
Micro-organism
Before French chemist Louis Pasteur began experimenting with bacteria in the 1860s, people did not know what caused disease. Not only did he discover that disease came from micro organisms, but also he realized that bacteria could be killed by heat and disinfectant (消毒剂). This idea caused doctors to wash their hands and disinfect their instruments, which has saved millions of lives.
Penicillin
Antibiotics(抗生素) are powerful drugs that kill dangerous bacteria in our bodies that make us sick. In 1928, British Alexander Fleming discovered the first antibiotic, penicillin, which he grew in his lab. Without antibiotics, infections like strep throat（脓毒性咽喉炎） could be deadly.
DNA
On February 28, 1853, James Watson of the United States and Francis Crick of England made one of the greatest scientific discoveries in history. The two scientists found the structure of DNA. Our genes are made of DNA and determine how things like what color hair and eye we’ll have. In 1962. they were awarded the Nobel Prize for this work. The discovery has helped doctors understand diseases and may someday prevent some illnesses like heart disease and cancer.
X-rays
Wilhelm Roentgen, a German physicist, discovered in X-rays in 1895. X-rays go right through some substances,like flesh and wood, but are stopped by others, such as bones and lead. This allows them to be used to see
broken bones or explosives inside suitcases, which makes them useful for doctors and security officers. For this discovery, Roentgen was awarded the first-ever Nobel Prize in Physics in 1901.
21. What did Louis Pasteur contribute to the world?
A. He discovered bacteria.
B. His findings helped save lives.
C. He found ways to grow bacteria.
D. His discovery won a Nobel Prize.
22. Which discovery was made by two scientists from different countries?
A. Micro-organism . B. Penicillin
C. DNA D. X-rays
23. Why is the discovery of X-rays important?
A. It can be used to see through bones and lead.
B. It can help us to know why we are different.
C. It is useful for doctor and security officers.
D. It is used to kill dangerous bacteria in our bodies.
24. What is common among the discoveries above？
A. They can help to prevent certain diseases.
B. They are all related to medical fields.
C. They are awarded the Nobel Prize.
D. They are all made in Europe.
