题目内容：

    Late blight (晚疫病) is a common disease of plants such as tomatoes and potatoes, capable of wiping out entire crops on commercial-sized fields. If conditions are favorable, it can quickly spread to other plants through wet soil and wind.

In history, late blight caused over 1 million deaths in Ireland. Today it still causes more than 6.7 billion dollars in annual losses worldwide. Small farms and growers are often the hardest hit, many stating losing almost two-thirds of their yearly production, because usually they don’t have money to identify and treat the disease.

But farmers may have a new weapon now. The technology, designed by researchers at North Carolina State University can recognize sick plants early by employing a piece of test paper that plugs into (接入) a reader on a smartphone.

Plants produce signaling chemicals from their leaves. “If a plant is diseased, the type and concentration of these chemicals changes,” said Wei Qingshan, an engineer at North Carolina State University. If the farmer suspects a late blight infection is underway, he can remove a leaf from a living plant and place it in a small, covered glass jar. After the leaf’s volatile (挥发性的) chemicals have accumulated for 15 minutes or so, the cap is removed and the air is pumped from the jar into a reader attached to the back of a smartphone. Inside the smartphone reader is a piece of paper specially treated with dyes (染料) by the researchers. Upon interacting (相互作用) with the plant’s volatile chemicals, the paper changes color to indicate the presence or absence of the late blight.

The researchers hope to tailor the technology for other crop diseases, which continue to appear as climate change and global trade increase the stress on agricultural systems. “This is an important step in the improvement of global food security,” Wei Qingshan said.

1.What are the statistics in Paragraph 2 mainly about?

A.The damage caused by late blight.

B.The money put into late blight treatment.

C.The number of crops in a commercial-sized field.

D.The yearly production of small farms and growers.

2.According to Wei Qingshan, how would a farmer find out if a plant was infected?

A.By treating the plant with special dyes.

B.By putting volatile chemicals on the plant.

C.By testing the air in the jar with a leaf inside.

D.By examining the land with a smartphone reader.

3.What do the researchers expect of their new technology?

A.It’ll reach farmers soon.

B.It’ll get rid of late blight.

C.It’ll be beneficial to the climate.

D.It’ll be able to detect more crop diseases.

4.What is the purpose of this passage?

A.To introduce a test method of late blight.

B.To explain the causes of late blight.

C.To discuss the effects of late blight.

D.To tell the history of late blight.