题目内容：

Scientists claim to have developed a revolutionary new giant 3D concrete printer that can build a 2,500-square-foot house in just 24 hours.

The 3D printer, developed by Professor Behrokh Khoshnevis from the University of Southern California, could be used to build a whole house, layer by layer, in a single day.

"It is basically scaling up 3D printing to the scale of building," said Khoshnevis.

The giant robot replaces construction workers with a nozzle (喷嘴), which can quickly build a home based on a computer pattern, MSN News reported.

Contour Crafting, as it is named, is a layered fabrication (构造) technology. Using this process, a single house or a colony of houses, each with possibly a different design, may be constructed in a single run, embedded (嵌入) in each house all the wires and pipes for electrical, plumbing and air-conditioning.

The potential applications of this technology are far-reaching including in emergency, low-income, and commercial housing.

"Our research also addresses the application of Contour Crafting in building habitats on other planets. Contour Crafting will most probably be one of the very few feasible approaches for building structures on other planets, such as the Moon and Mars, which are being targeted for human habitation before the end of the new century," researchers said on the project website.

The technology may potentially reduce energy use and emissions. And the main advantages of the Contour Crafting process over existing technologies are the superior surface finish that is realized and the greatly increased speed of construction.

1.Professor Khoshnevis has recently developed a 3D printer that can ________.

A. build a 2500-square-foot house in a single day

B. construct a skyscraper, layer by layer

C. design a group of houses automatically

D. assist construction workers in their work

2.The new 3D printer uses the following to build a house EXCEPT ________.

A. a nozzle    B. a computer pattern    C. a robot    D. an air-conditioner

3.According to the text, the potential applications of Contour Crafting include building _______.

A. emergency vehicles    B. low-income housing

C. commercial centers    D. space stations on other planets

4.What advantages of this new technology is mentioned in the text?

A. It creates more jobs.    B. It is less time-consuming.

C. It saves the building cost.    D. It emits no carbon dioxide.