The six-wheeled Scout is about the size of a large cooler with the capacity to carry small or medium-sized packages. The battery-powered vehicle, which moves at a regular walking pace, has been programmed to avoid pedestrians, animals, and unexpected obstacles, such as garbage cans. Its powerful sensors can also detect the movement of a car backing out of a driveway.

To accelerate Scout’s development and bring it nationwide sooner, the company has created several detailed virtual maps of American suburbs and conducted trial deliveries to homes there.

Though Amazon has not shown how Scout ensures the delivery is picked up by the right person, it most likely requires the customers to apply a unique code, texted to them prior to the delivery, to unlock the store box. Also unclear is the number of deliveries Scout can complete before its battery needs to be recharged. Though the initial tests are being conducted with a human for company, the robot will be autonomous in the future. Its location, however, will be tracked at all times—if someone attempts to steal Scout, Amazon employees will be instantly sensed.

However, the eco-friendly robots are unable to climb stairs or open gates, which means that they can only reach consumers who live on the ground level. Additionally, the robots are unable to leave packages at the front door if the customers are not home. Whether these problems get resolved remains to be seen. For now, it appears that humans will still be needed to achieve the ever-growing demand for home and office deliveries.

【1】Which of the following descriptions about Scout is right?

A.They can be powered themselves. B.They are strong enough to carry big things.

C.They can run with their six wheels. D.They can avoid obstacles ahead.

【2】What about Scout is still confusing to common people?

A.How many deliveries it can do on a full charge. B.Whether it can climb stairs or open gates.

C.How it recognizes the right owner of the things. D.How long it will take to get it fully charged.

【3】What does the underlined phrase “prior to” in paragraph 4 mean?

A.due to B.after C.in front of D.before

【4】What is the author’s opinion about delivery robots according to the last paragraph?

A.They are not easily available. B.They have some limitations.

C.They will replace humans soon. D.They won’t be well accepted.