On September 3, 1928, Alexander Fleming was hard at work. His________ was to study bacteria in a lab. While working, Fleming found mold (霉菌) on one of his Petri dishes. And when he looked ________, he saw something ________. The bacteria he studied were also________ all over the dish, but they weren’t growing on the spots that had mold. He ________ whether the bacteria were driven away by the mold. After more tests, Fleming found that it was doing just that. And he learned that the mold was a ________called Penicillin.

Fleming believed that he could turn the mold into medicine to ________ infections. This medicine was the world’s first antibiotic (抗生素). Fleming first ________ it “mold juice”. Later, he ________ the name to “penicillin”. Soon, a team at Oxford University ________ to help. Scientists Howard Florey, Ernst Chain and Norman Heatley worked with Fleming. Together, they further ________ penicillin.

The first patient treated with the new drug had a bad ________. His name was Albert Alexander. After a few ________ with penicillin, he felt much better. However, they ________ the medicine. The infection came back, and ________ Alexander passed away. Still, the doctors had learned that penicillin could fight bacteria. They just needed to ________ more of it. Later, Florey and Chain flew to the United States. There, they found ways to grow the mold________. Starting in 1942, penicillin was used to treat World WarⅡsoldiers.

At that time, diseases were just as ________ for soldiers at war as enemy forces were. Bacterial pneumonia (肺炎) alone ________ 18% of American soldiers to die in the first World War. Thanks to penicillin, that ________ to less than one percent in World WarⅡ.

The four scientists saved lives and changed the world of medicine forever. Today, antibiotics are used to treat many illnesses.

Whether it’s from an awful breakup or a painful life event, some memories can return repeatedly to our mind for the entire lives. But, what if science can ______ your bad memories so that you can start all over again? As is known to all, memory is an incredibly complex _______. While scientists used to believe it was like a filing cabinet and particular memories were stored in different sections of the brain, we now know this is ______.

In fact, each memory is a brain wide process. If you end up remembering something, it’s because the cells in your brain are being fired, ______ new connections and links and literally rebuild the circuitry of your mind. And this change is partially ______ by proteins in the brain. So what if the proteins aren’t available?

Simply put, memories can’t be made. Seriously, scientists have tested this by giving animals drugs that prevent these proteins from forming. ______, the animals have no recollection of the things that took place shortly after the drug was taken. From this research, scientists actually found a way to target long-term memories for ______. You see, every single time you remember a memory, your brain is once again firing and rewiring.

In fact, each time you reflect on a memory, you are physically changing that memory in your mind. And each time the memory is changed a little, it reflects your ______ thoughts. Remembering, to a great extent, is an act of ______ and imagination, which means that the more you reflect on old memories, the less accurate they will become. And scientists have actually quantified this change.

After 9/11, hundreds of people were asked about their memories of the dreadful day. A year later, 37% of the details had changed. By 2004, nearly 50% of the details had changed or gone ______. And because memories are formed and rebuilt every time, if you administer (服药) the protein-preventing drug while recalling a memory, the memory can be ______ removed.

To test this, scientists took lab rats and played sound for them, shortly followed by an electric shock. ______ doing this for many times, the rats quickly learned that if they heard the sound, a shock was soon to follow. Therefore, they would stress up and freeze every time they heard it. Months later, these rats would still ______ the noise. However, if they administered the drug first, the rats would lose the memory of the sound, and simply continue on. They had lost their memory of that specific noise.

To be sure that the drug wasn’t just causing large-scale brain damage, scientists repeated these experiments with various tones this time. Both sounds would warn for a shock and ______ the rats would fear both. But if they administered the drug and played only one of the sounds, the mice would only forget that one tone, while still remaining ______ of the other. Over time scientists have discovered specific drugs to target particular proteins across different parts of the brain.

No area of technology is hotter than AI, or artificial intelligence. Venture-capital investment in AI in the first nine months of 2017 totalled $7.6bn, according to PitchBook, a data provider, that compares with full-year figures of $5.4bn in 2016.

At the heart of the _________ are some familiar names: the likes of Amazon, Apple, Microsoft…. Several have put AI at the centre of their strategies. They see AI as a way to improve their _________ services, and to push into new areas like driverless cars. Many observers fear that, by cementing and extending the power of a handful of giants, AI will _________ competition. That will depend on two open questions.

The first one is whether AI will always _________ vast amounts of data. Machines today are usually trained on huge datasets, from which they can recognise useful patterns such as illegal financial behaviors. _________ real-world data remain essential to AI, the tech superstars enjoy the biggest advantage. They have vast amounts of the stuff, and are gaining more as they push into _________ areas such as health care.

A competing vision of AI stresses simulations, in which machines teach themselves using synthetic data or in virtual environments. Early versions of a program developed to play Go, an Asian board game, by DeepMind, a unit of Alphabet were trained using data from _________ games; the latest was simply given the rules and started playing Go against itself. Within three days it had done better than its predecessor (前辈), which had itself beaten by the best human player. If this approach is widely _________, or if future AI systems can be trained using small amounts of data, the tech giants will obviously lose their advantage.

The other question is how openly _________ will be shared. The tech giants’ ability to employ AI expertise from universities is helped by their willingness to __________ research; Google and Facebook have opened software libraries to outside developers. But their __________ to share valuable data and algorithms are weak. Much will depend on whether there will be relevant regulations. __________, Europe’s data-protection rules that will take effect soon require firms to get approval for how they use data and to make it easier for customers to __________ their information to other providers.

The battle in AI is fiercest among the tech giants. It is too early to know how good that will be for competition, but not to __________ the magic ingredient that will determine the outcome: the importance, __________ and openness of data.