单项选择题

When one of your car tires goes flat, there are two things you can do. Groan and change it or, if you don’’t have a spare, stand helplessly beside the road and hope someone comes to your rescue. Now comes a third alternative, called Quickwheel. It is designed to get disabled motorists rolling again as quickly as possible. Quickwheel is essentially a tiny emergency trailer—complete with three tough little wheels of its own—that supports the flat tire and enables the motorist to drive to a service station without losing much time or expending much energy. The product is manufactured in the Netherlands but is owned and marketed by a U. S. company, Quickwheel Inc. of Greenwich, Connecticut. According to the firm’’s president, Robert Bockweg, the product meets each of the major concerns that consumers associate with flat tires: safety, lost time and physical exertion. To use it, motorists simply unfold the product to its fully extended position, set it in front of the disabled tire, drive the car onto the Quickwheel’’s ramp and attach a special safety strap (皮带) over the tire, the tire is then locked, or cradled in Quickwheel’’s metal frame. The device’’s three wheels do the rest of the work. According to Quickwheel Inc. , its product can be driven "for miles" at speed of up to 45 miles per hour "without any noticeable change in the vehicle’’s braking or steering operation". The company also claims that it can be used on just about any type of car, jeep, mini-van or trailer. Bockweg says that Quickwheel will be sold initially in the United States, at a price of $ 150. Distribution agreements now being negotiated should make the product available in Japan, Canada and Western Europe in the near future. Which of the following is NOT mentioned as an advantage of Quickwheel