The history of the flying car is almost as old as that of powered flight itself. It started with the Curtiss Autoplane of 1917, an awkward-looking contraption with detachable wings. It never left the ground, Later machines made it into the skies but failed to take off commercially. Money is now pouring into flying taxix. On March 30th Lilium, a German company that develops them, announced a reverse merger with a special-purpose acquisition company (SPAC) that values it at $3.3 bn — a sign that investors think the business will fly.

Thanks to better batteries and lightweight materials the vehicles, some of them ten years in the making, are ready to carry passengers. Up to 300 firms are working on short-range battery-powered craft that take off and land vertically (垂直的), estimates Natasha Santha of LEK, a consultancy. Carmakers, aerospace firms, tech companies and others are ploughing (大量投资) money into the field. Morgan Stanley, an investment bank, reckons the market for aerial hops could be worth $674 bn by 2040. Regulators are offering a glide path to certification. America’s Federal Aviation Administration is engaged in the process with around 30 firms, Ms. Santha says. Others besides Lilium are heading for the stock-market, after mergers with SPACs. One of them, Joby Aviation, has been valued at nearly $7 bn. Another, Archer, is worth almost $4 bn.

Midway between a cab and a helicopter, flying taxis have distinct advantages over both. Quiet electric motors allow them to operate frequent services. They require only a patch of concrete to land, unlike noisy choppers, which face severe operating restrictions in most cities. They can fly four or five times faster than a cab can drive and do not get stuck in traffic. Prices can be kept low by ride-sharing.

Joby, based in California, says its five-seater machine will enter commercial service in 2024. The firm calculates the initial cost of around $4 per person per mile may soon fall by 25%. A trip from Manhattan to JFK airport would then cost $30-40 per passenger. It counts Toyota, a Japanese car giant, among its backers and in December it acquired the flying-car business of Uber, a ride-hailing titan. As it announced its listing via a SPAC in February, Archer unveiled a $1bn deal to supply United Airlines and a partner airline with 200 five-seater craft. It promises flying-taxi networks in Los Angeles and Miami by 2024.

Some companies are even closer to lift-off. One, eHang, is close to certification in China, its home market. In Europe Volocopter, a German firm backed by two car companies, Daimler and Geely, as well as Intel, a chip-maker, and DB Schenker, a logistics giant, hopes to be allowed to fly in 2023. It plans to start service soon afterwards. Other startups such as Vertical Aerospace, a British company, as well as familiar names in car-making (Hyundai of South Korea) and plane-making (Airbus in Europe) are not far behind.

The real revolution will come when full autonomy takes out the cost of a pilot. Archer hopes to run such aircraft by 2028. They face fewer obstacles in the air than earth-bound cars do on the road; airlines mostly fly on autopilot as it is. Still, as one industry insider puts it, it is probably best to accustom passengers and regulators to airborne taxis before ejecting (辞退) the driver.

During these days, the United States is full of cars. There are still some families without cars, but some families have two or more ones. 【小题1】They are also a necessary part of life.

Cars are used for business. They are driven to offices and factories by workers who have no other way to get to their jobs. When salesmen are sent to different parts of the city, they have to drive in order to carry their products. 【小题2】

Sometimes small children must be driven to school. In some cities school buses are used only when children live more than a mile away from the school. 【小题3】   One mother drives on Mondays taking her own children and the neighbors’ as well. Another mother drives on Tuesdays, another on Wednesdays, and so on. 【小题4】   Men also form car pools, with three or four men taking turns driving to the place where they all work.

【小题5】 So more car pools should be formed in order to put fewer cars on the road and use less gas. Too many cars will lead to some problems such as accidents or environmental pollution. Something will have to be done about the use of cars. And the government should encourage the citizens to decrease the use of their cars as much as they can.

How does drone (无人机) delivery work? Let’s say you want to buy Mom a box of chocolates. You look for just the right kind for the right price at an online shop that offers drone deliveries. 【小题1】 Wing’s drones, for example, can carry a package only up to 1.5 kg in weight. Say you place your order using Wing’s mobile app. The shop packs up your order in a specialized package and requests a drone. 【小题2】 A computer mapping system calculates the best route from the shop to your location and then uploads the flight path to the drone’s computer. As it hovers above the shop’s pick-up area, someone from the shop connects the package to a tether (系绳) hanging below the drone. Now it flies off to you.

Meanwhile back at your place, your phone pings. Chocolates on their way! You can track the drone traveling toward you. 【小题3】 When the package lands on the ground, the tether releases the package. The drone buzzes back up to cruising height and returns to the company’s site, called the Nest. It lands on a charging pad, preparing for the next delivery. You give the chocolates to your mom. Smiles all around!

All sounds good, right? 【小题4】 Some say these flying robots are disturbingly noisy. Others worry that drones are not safe because a few pilots will ignore the rules or that drones will make the skies too crowded.

Wing’s spokesperson says the company’s engineers have programmed drone computers to find clear routes for delivery avoiding obstacles like trees, buildings and power lines. If a problem arises during a flight, multiple systems—motors, batteries, and navigation—back up the power and guidance systems.【小题5】