In New Jersey,there's a row of houses with a green lawn(草坪) that kids can't enjoy."It's really frustrating. These lawns are useless to me,”Alice,a suburban mom in New Jersey said. She lives in a beautiful community full of green lawns.

It's the middle of summer, but there are no dandelions in sight. And that's the problem: the lawns are so green because they’re full of pesticides, Warning signs urge parents to keep kids off the chemical-laden grass.

Alice says that most lawns and parks in her area are like this.There are plenty of them,but her kids can't play in them.“I just want to let my baby experience the grass," she said. “ Also, I'm sure it's not good for animals. The other day, a woman found a dead deer in her backyard."

In the 1940s, people often mixed clover with grass to keep lawns strong, which benefited the environment. But over the last few decades, pesticides have taken over. In 2012, the world spent $ 56 billion on pesticides. They go into farms, lawns, parks and just about anywhere where humans grow plants. These chemicals keep parks' grass and flowers perfect. They just make them useless as actual parks.

That may be more than just annoying. New research has shown that play is good for kids. It helps them discover the world and learn how to get along with other people. But it's hard to get enough play when there are so few public spaces where kids can play. And the few that exist are often covered in chemicals that make parents uncomfortable.

There are things to take the place of pesticides, like planting a lawn full of clover, Besides, maybe a dandelion here or there isn't the worst thing.

It started during a yoga class. She felt a strange pull on her neck, a feeling completely foreign to her. Her friend suggested she, rush to the emergency room. It turned out that she was having a heart attack.

She didn’t share similar symptoms with someone who was likely to have a heart attack. She exercised, watched her plate and did not smoke. But on reviewing her medical history, I found that her cholesterol （胆固醇）level was sky-high. She had been prescribed a cholesterol-lowering statin medication, but she never picked up the prescription because of the scary things she had read about statins on the Internet. She was the victim of fake medical news.

While misinformation has been the object of great attention in politics, medical misinformation might lead to an increase in deaths. As is true with fake news in general, medical lies tend to spread further than truths on the Internet----- and they have very real bad consequences.

False medical information can also lead to patients experiencing greater side effects through the “nocebo effect （无安慰剂效应）Sometimes patients benefit from an intervention （干预）simply because they believe they will — that’s the placebo effect （安慰剂效应）.The nocebo effect is the opposite. Patients can experience harmful effects because they anticipate them. This is very true of statins. In blinded trials, patients who get statins are no more likely to report feeling muscle aches than patients who get a placebo. Yet, in clinical practice, according to one study, almost a fifth of patients taking statins report side effects, leading many to discontinue the drugs.

What else is on the fake news hit list? As always, vaccines （疫苗）.False concerns that the vaccine may cause side effects have greatly reduced coverage rates.

Cancer is another big target for pushers of medical misinformation — many of whom refuse alternative therapies. “Though most people think cancer tumors are bad, they’re actually the way your body attempts to contain the harmful cells,”^, one fake news story reads. It warns that prescription medications lead to the uncontrolled cell mutations （变异）.

Silicon Valley needs to face this problem. I am not a free-speech lawyer, but when human health is at risk, perhaps search engines, social media platforms and websites should be held responsible for promoting or hosting fake information. Meanwhile, journalists should do a better job of spreading accurate information.

Could you reproduce Silicon Valley elsewhere, or is there something unique about it? It wouldn’t be surprising if it were hard to reproduce in other countries, because you couldn’t reproduce it in most of the US either. What does it take to make a Silicon Valley?

【小题1】If you could get the right ten thousand people to move from Silicon Valley to Buffalo, Buffalo would become Silicon Valley. You only need two kinds of people to create a technology hub (中心): rich people and nerds (痴迷科研的人). Observation bears this out. Within the US, towns have become startup hubs if and only if they have both rich people and nerds. Few startups happen in Miami, for example, because although it’s full of rich people, it has few nerds. 【小题2】

Whereas, Pittsburg has the opposite problem: plenty ofnerds, but no rich people. The top Us Computer Science departments are said to be MIT, Stanford, Berkeley, and Carnegie-Mellon. MIT yielded Route 128. Stanford and Berkeley yielded Silicon Valley. But what did Carnegie-Mellon yield in Pittsburgh? And what happened in Ithaca, home of Cornell University, which is also high on the list?

I grew up in Pittsburgh and went to college at Cornell, so I can answer for both. The weather is terrible, particularly in winter, and there’s no interesting old city to make up for it, as there is in Boston. 【小题3】. So while there are plenty of hackers who could start startups, there’s no one to invest in them.

Do you really need the rich people? Wouldn’t it work to have the government invest the nerds? No, it would not. Startup investors are a distinct type of rich people. 【小题4】 This helps them pick the right startups, and means they can supply advice and connections as well as money. And the fact that they have a personal stake in the outcome makes them really pay attention.