Here’s a piece of good news. After years’ research and testing, the hybrid car is developed and put on the market. It’s an interesting and exciting new improvement in today’s world as we look for better ways to protect the quality of the air we breathe and conserve (节约) our natural resources.

The quality of our air is affected by many different things. But one of the largest sources of air pollution is the burning of fossil fuels such as coal and gasoline which is used to power a car’s engine. The EPA has set national standards to help control the level of harmful pollutants sent off into the air, and the automobile industry has acted by producing a hybrid car that uses less gas and therefore causes less pollution.

A hybrid car is a combination of a regular car that runs on gasoline and an electric car that is powered by battery. Some people tend to think that since the hybrid car is partially electric, you have to plug (接通电源) it in to charge it. But that’s not how it works. The 144-volt battery pack is actually recharged through the energy that is produced when the car’s brakes are used. This is referred to as “regenerative braking”, because it generates electricity.

Although the hybrid car still runs on gasoline most of the time, it uses less gas than a regular car. When the driver stops at a traffic light, the engine automatically shuts off to save fuel. Then, as soon as the driver puts the car in gear and touches the gas pedal, the engine starts back up.

Have you ever ridden in a car with someone who ran out of gas? That probably wouldn’t happen if you were riding in a hybrid car. It flashes a warning on its computer screen that says, “I am low on gas.” When it completely runs out, the warning reads, “YOU ARE NOW OUT OF GAS!” Then the electric power supply kicks in (起作用) to let the driver travel a few more miles to a gas station.

The connection between people and plants has long been the subject of scientific research. Recent studies have found positive effects. A study conducted in Youngstown, Ohio, for example, discovered that greener areas of the city experienced less crime. In another, employees were shown to be 15% more productive when their workplaces were decorated with houseplants.

The engineers at the Massachusetts Institute of Technology (MIT) have taken it a step further—changing the actual composition (构成) of plants in order to get them to perform different, even unusual functions. These include plants that have sensors (传感器) printed onto their leaves to show when they’re short of water and a plant that can detect chemicals in groundwater. “We’re thinking about how we can engineer plants to change the functions of the things that we use every day,” explained Michale Strano, a professor of chemical engineering at MIT.

One of his latest projects has been to make plants glow (发光) in experiments using some common vegetables. Strano’s team found that they could create a weak light for 3.5 hours. The light, about 1000th of the amount needed to read by, is just a start. “The technology,” Strano said, “could one day be used to light the rooms or even to turn trees into self-powered street lamps.”

In the future, the team hopes to develop a kind of the technology that can be sprayed onto plant leaves only once but would last the plant’s lifetime. The engineers are also trying to develop an on and off “switch” where the glow would slowly disappear when the day breaks.

Lighting accounts for about 7% of the total electricity used in the US. Since lighting is often far removed from the power source—such as the distance from a power plant to street lamps on a remote highway—a lot of energy is lost during transmission (传输). Glowing plants could reduce this distance and therefore help save energy.