Many people often     1     when they go to work. How annoyed and stressful they often feel! But the problem is that the number of cars is still going up. Traffic pollution has been found to       2     and climate change to a large degree.

Too many cars     3     to the environment and our health. Some advice has been given for people to help     4     , for example, using public transport or     5     , doing your shopping in the shop just around the corner instead of driving to the other side of town. However, people       6     using cars. They     7     for using their cars, “I need to     8     my daughter. What can I do?”

Amsterdam has become very popular with cyclists because of the convenience for bicycles. In the 1960s, a group of cycling fans came up with an idea     1    (make) Amsterdam the city of bikes. People had hundreds of bicycles     2    (paint) white and anyone was allowed to take them. They were hopeful that this would save energy, reduce pollution and provide free public transport. However, thieves stole them all. In 1999, the “white bikes” returned with a computer     3    (track) system to record their every move. It worked this time. Nowadays people can enjoy clean air and easy transport in central Amsterdam and bike-sharing is gaining favors across the globe. In China, many people are devoting     4    (them) to solving problems so that people can enjoy the benefits of shared-bikes.

Some bullet trains don’t run on tracks at all. They fly over them. They     1    (call) maglev bullet trains(磁悬浮高速列车)，and they use two groups of magnets to move. One group pushes the trains up and off the tracks and the other group pushes the trains forward,     2    makes the trains go much faster and make less noise, too. The world’s     3    (fast) train now is a maglev train in China. It has a maximum speed of 600 kilometers per hour.

10 . When it comes to lowering our carbon emissions (排放), it seems that nothing is simple. Electric vehicles (EVs) act as an example of potential greenwash. “They seem very attractive at first sight,” writes The Next Web in a report. “When we look more closely, it becomes clear that they have a substantial carbon footprint.”

The rare earth metals and costly minerals included as essential ingredients in EV batteries are not renewable. What’s more, their extraction (提炼) is often anything but green.

So the question is: is it worth it? Just how much emission reduction can EVs justify? Luckily, a life cycle assessment has been done to give us some answers.

“A life cycle analysis of emissions considers three phases,” writes The Next Web. “the manufacturing phase, the use phase, and the recycling phase.” In the manufacturing phase, the battery is to blame. “Emissions from manufacturing EV batteries were estimated to be 3.2 tons of carbon dioxide (CO2), 1/4 of those from an electric car, 13 tons of CO2. Those were bigger than emissions from gas cars, 10.5 tons of CO2.” If the vehicle life is assumed to be 150,000 kilometers, emissions from the manufacturing phase of an electric car are higher than gas cars.”

In the use phase, the source of electricity the consumer is using to power their car comes into play in a major way. “To understand how the emissions of electric car vary with a country’s renewable electricity share, consider Australia and New Zealand,” continues the report. “In 2018, Australia’s share of renewables in electricity was about 21%. In contrast, the number in New Zealand’s was about 84%. Electric car emissions in Australia and New Zealand are estimated at about 170g and 25g of CO2 per km respectively. As a consumer, our car is only as green as our country’s energy mix.”

Finally, in the recycling phase, we look at vehicle dismantling(拆除), vehicle recycling, battery recycling, and material recovery. “The estimated emissions in this phase, based on a study, are about 1.8 tons for a gas car and 2.4 tons for an electric car. This difference is mostly due to the emissions from battery recycling, which is 0.7 tons,” shows in the report. “While electric cars cause more greenhouse gas emissions than gas cars do, it's important to note the recycled batteries can be used in subsequent batteries. This could have significant emissions reduction benefits in the future. For complete life cycle emissions, the study shows that EV emissions are 18% lower than gas cars.”

So here’s the takeaway: EVs are greener. Maybe they’re not as green as we thought. There’s certainly room for improvement. But the real challenge lies in speeding the global energy transition toward greener energy-production.