题目内容：

A machine which makes water out of air could become the greatest household invention since the microwave． Using the same technology as a dehumidifier (除湿器)， the Water Mill is able to create a ready supply of drinking water by getting it from a limitless source－the air． The company behind the machine says not only does it offer all alterative to bottled water in developed countries，but it is a solution for the millions who face a daily water shortage．

The machine works by drawing in damp air through a filter(过滤器) and over a cooling element which changes it into water droplets．It can produce up to 12 liters a day．The Water Mill will also produce more water when storms pass over, as the humidity（湿度）in the air increases．In keeping with its ecodevelopment，the machine uses the same amount of electricity as three light bulbs．

  Inventor Jonathan Ritchey said：“The demand for water is off the chart．People are looking for freedom from water distribution systems that are shaky and unreliable”．

  The machine，which is about 3 feet wide，is likely to cost￡800 when it goes on sale here in the spring．Its maker, Canadian firm Element Four, estimates that a liter of water will cost around 20 pence to produce．

  Environmentalists claim half the world’s population will face water shortage because of climate change by 2080．One in five humans is said to lack access to safe drinking water．

  The Water Mill is not effective in areas with below about 30 percent relative humidity, but with average relative humidity in England of more than 70 percent that won’t be much of an issue here.

1.According to the author, the biggest advantage of the machine is its ______．

A．little power use  B．unlimited source  C．proper size  D．high production

2.We can conclude from the passage that the machine________．

A．can be used everywhere

B．has not been on sale

C．will replace the water distribution system

D．will solve the problem of water shortage

3.The underlined phrase “off the chart” in the passage means ________

A．record-breaking．  B．urgent．  C．unbelievable．D．amazing．

4.What would be the best title for this passage?________

A．Microwave for Household Use     B．Filter to Draw in Damp Air         

C．Mode Dehumidifier on Sale        D．Machine to Make Water out of Air