题目内容：

    Technology has become so advanced that the previously impossible seems to occur on a daily basis. And yet — we still have no cure for the common cold.

According to Peter Barlow, a scientist at Edinburgh Napier University in the UK, the main challenge lies in the many different types of cold viruses. There are at least 160 types. They changed so easily that they quickly become resistant to drugs, or learn to hide from our immune systems. In other words, a single cure isn’t likely to work on every type of cold.

However, researchers from Stanford University have found a possible answer. They discovered a protein that the viruses need. Without it, they can’t spread inside your body. To  identify the gene(基因) which produces the specific protein needed by the viruses, researchers used a gene-editing technique to test all genes. These modified (改变的) cells were then exposed to a range of viruses, including ones causing the common cold. All the viruses were unable to replicate (复制) inside cells without a gene that produces that specific protein.

Then, they tested genetically modified mice, which were completely unable to produce the protein. The mice were able to live normal lives without the protein. “Lacking that gene protected the mice completely from viral infection,” associate professor Jan Carette, from Stanford, told the BBC. “These mice would always die, but they lived through and we saw a very strong reduction in copying viruses and very strong protection. We have identified a fantastic target that all cold viruses require and depend on. Take that away and the virus really has no chance. ”

Carette said the plan is to find a drug which can temporarily control the protein, instead of producing genetically modified humans.

1.Which of the following can best describe common cold viruses?

A.Severe and deadly. B.Mysterious and stubborn.

C.Diverse and changeable. D.Challenging and oversized.

2.How does the protein work?

A.Help viruses spread. B.Reduce physical infection.

C.Fight against other viruses. D.Strengthen the immune system.

3.What can we learn about the genetically modified mice?

A.They caught cold easily. B.Their health worsened.

C.They produced more protein. D.They were able to survive,

4.What is purpose of the research?

A.To control certain genes. B.To conquer the common cold.

C.To test a new drug. D.To cure genetically modified mice.