B
What is the dirtiest thing in our home? The toilet? Wrong! Scientists in the US have found that electronic devices are even dirtier.
The scientists took samples from 38 electronic devices and other things like toilet seats. They then counted the bacteria colonies (细菌菌落) — groups of bacteria that grow together.
The dirtiest of all turned out to be headphones (耳机). The scientists found 1,073 colonies on the headphones of an average person. That is twice as many as a toilet seat with 425 colonies on average. The sweat and heat from our ears and heads may be the reason. They make a nice environment for bacteria to grow.
Smartphones are quite clean among the devices we often use. Each has only about 187 colonies, but we also touch smartphones the most. When we eat or sleep, we often put them right by our side, so the chance of catching bacteria from them is big.
Some bacteria, like pseudomonas (假单胞菌), can make us very sick. The scientists found them on headphones and computer mice. “They can cause pimples (粉刺) and serious problems for our eyes, ears and lungs (肺),” said the Cleveland Clinic in the US.
So, we should clean our electronic devices often after we finish using them. It is also important to wash our hands before eating and keep our devices away from the dining table.
(
C
) 5. What did the scientists find from their research?
A. Headphones have 425 colonies on average.
B. Bacteria usually grow together in colonies.
C. Headphones are the dirtiest electronic devices.
D. Electronic devices are not as dirty as people thought.
(
A
) 6. Why could it be easy to catch bacteria from smartphones?
A. Because people use them very often.
B. Because people never clean them after use.
C. Because they have the largest bacteria colonies.
D. Because they offer a nice place for bacteria to grow.
(
D
) 7. Paragraph 5 mainly talks about
.
A. other electronic devices with bacteria
B. the serious problems of using smartphones
C. the bacteria that can live in human bodies
D. the dangers of some bacteria on electronic devices
(
A
) 8. How can we protect ourselves from the bacteria on electronic devices according to the passage?
A. By cleaning the electronic devices often.
B. By washing our hands before touching them.
C. By turning them off during eating or sleeping.
D. By putting them on the table while using them.
