3 . It’s often said, “You can’t live only on air.” But now the Chinese scientists can tell you: Maybe you can.

Recently, some Chinese scientists have made a big breakthrough (突破). They turned CO₂ into starch (淀粉).

Starch is the main part of rice and corn that we eat every day. Usually, it’s created by plants with CO₂, water and sunlight. According to the team’s director Ma Yanhe, it takes the plants nearly sixty steps to produce starch. But now, the team, after six years of hard work, has found a simpler way to do this, with only eleven steps.

“Our study shows that creating something like starch is possible in a laboratory, and this technology may be helpful in many areas,” said Ma.

The scientists first turned CO₂ and hydrogen (氢气) into methanol (甲醇). Then they made these methanol molecules (分子) into bigger and more complex (复杂的) molecules. Finally the starch came out.

This method makes it possible to produce food in factories instead of traditional farming. This will not only help make plenty of food, but also save water and land. It may also help recycle CO₂ to deal with climate (气候) change, according to China Daily.

The study can be helpful in space, too. Astronauts may no longer need to worry about their food as they travel in space. They may simply turn the CO₂ they breathe out into the food they eat!

4 . Robots may seem smart, but they cannot even pick up a chess piece. Let’s take a look at some tasks that are easy for kids but not for robots.

Pick things up

Picking things up is not easy. If we drop our pencil on the floor, our brains work hard. First, we must find the pencil. Then we move our hands to it. A robot cannot always move its “hand” to the right place. When we touch the pencil, it might roll（滚动） a little bit. Robots cannot easily understand this either. So, if you drop a pencil on the floor, a robot will probably roll it around the room.

Get around in large space

If someone drops us in a building we’ve never been to, we might feel a bit lost. But we can look around, find a door and get out quickly. But a robot will look everywhere for a door, even on ceilings（天花板） and floors. This is because it’s hard for them to understand spaces, especially large, blank things such as walls or ceilings.

Understand the world made by people

“Common sense” is what we don’t need to think or talk about. Because of common sense, we do not look for doors on the ceiling. We pick up a coffee cup by its handle（把手）. We feel whether it has coffee inside, and whether it’s hot.

A robot? It may turn the cup upside down. It may hold the hot part of the cup. Scientists have tried teaching robots common-sense rules. But even huge databases（数据库） don’t help much. Maybe they need more time to learn.

The human population on Earth grows larger each year. As a result,     1    . Because of climate change（气候变化）, growing more food is becoming even more difficult.

When farmers tried to grow more food in the past, they would use farming methods that weren’t always healthy for the environment. To solve this problem,     2    . They spent several years talking to farmers. They wanted to see what problems farmers were having and how these problems could be solved.     3    . These special robots move around on farms and collect information about crops（庄稼）. They can take pictures of plants, track（追踪）each plant’s growth and measure（测量）its size.

In the past, though farmers did have information about the weather and the earth, they couldn’t track each plant.     4    .

By collecting information about plants, the robots can help farmers make predictions（预测）about how their plants will grow.     5    . For example, if the robots find out which plants get sick, farmers can quickly throw them away before they are about to influence nearby plants. With the help of these robots, farmers can take better care of the plants in need.