New Findings on Cancer

Scientists have learned more about the way cancer spreads from one place in the body to another. Once it spreads, it gets more difficult to treat. Cancer is a disease of uncontrolled cell growth. Traditional thinking is that cells simply break off the main cancer, travel through the blood and grow in other organs.

But the new findings suggest there is more to this process. Researchers found that cells from the main tumor（瘤） send out messengers（送信者）. These prepare the new organ for a secondary tumor.

It works this way. The primary tumor releases （釋放） proteins called growth factors into the blood. They signal cells at the target organ to produce a sticky protein, called fibronectin. Fibronectin attaches to the surface of bone marrow （骨髓） cells. The result is a kind of landing area for cancer to arrive and grow into a secondary tumor.

The bone marrow (骨髓）cells help make vessels （血管） for blood to pass through and feed the cancer cells. The researchers believe that without the bone marrow cells, the tumors could not land on the new organ and grow.

Scientists from Cornell University in Ithaca, New York, led the research. The study appeared in the publication Nature. It involved laboratory mice. The researchers killed off bone marrow cells in the animals and replaced them with special new ones, which were brightly colored, so the researchers could observe them. The mice were then injected with lung cancer cells.

The researchers were surprised when the bone marrow cells reached the lungs days before any cancer cells. They found that the bone marrow cells arrived to prepare the lungs for the cancer to spread. Other tests led to similar findings.

The researchers believe they would find the same result in humans. They say knowledge of the process could lead to new ways to fight cancer.

1.It is more difficult to control the cancer after it spreads

A.Right　B.Wrong　C.Not mentioned

正確答案:A

解析:該題說的是：癌癥擴散了之后就更不好控制了。第一段中間提到一旦擴散，就更不容易治療了。這里的“treat”與題干中的“control”都是對癌癥的治療的意思

2.People used to believe that some cancer cells just got away from main cancer and travelled through blood vessels to other organs and grow there

A.Right　B.Wrong　C.Not mentioned

正確答案:A

解析:該題說的是：過去人們認為一些癌細胞從主細胞上分離，通過血管移動到其它器官并在那里生長。第一段最后一句就是這個意思。其中的“Traditional thinking”就是傳統(tǒng)的認為，也就是過去認為。因此正確

3.Actually, the primary tumor sends out proteins instead of cancer cells

A.Right　B.Wrong　C.Not mentioned

正確答案:A

解析:該題說的是：事實上，腫瘤主細胞釋放出的是蛋白質(zhì)，而不是癌細胞。第三段開頭提到“The primary tumor releases proteins”意思就是主腫瘤釋放出蛋白質(zhì)

4.The bone marrow cells play an unimportant role in the nourishment of the secondary tumor

A.Right　B.Wrong　C.Not mentioned

正確答案:B

解析:該題說的是：骨髓細胞在繼發(fā)瘤的營養(yǎng)補給方面不起重要作用。從第四段可知，骨髓細胞能夠制造血管，為繼發(fā)瘤細胞輸送營養(yǎng)。因此提高說法不正確

5.The researchers killed a lot of mice for the laboratory test

A.Right　B.Wrong　C.Not mentioned

正確答案:B

解析:該題說的是：為了實驗研究院們殺死了許多老鼠。第五段提到“The researchers killed off bone marrow cells in the animals and replaced them with special new ones, which were brightly colored,”這句話的意思是研究員們殺死了老鼠體內(nèi)的骨髓細胞，并代之以做了發(fā)光標記的新骨髓細胞。就是說，他們殺死的并不是老鼠，而是細胞。因此題干錯誤

6.Lung cancer cells reached the lung of the lab mice much earlier than the bone marrow cells

A.Right　B.Wrong　C.Not mentioned

正確答案:B

解析:該題說的是：肺癌細胞比骨髓細胞更早到達了老鼠肺內(nèi)。倒數(shù)第二段中提到骨髓細胞比癌細胞早到達肺部好幾天。所以題干的說法是錯誤的

7.All the mice involved in the lab test died of lung cancer at last

A.Right　B.Wrong　C.Not mentioned

正確答案:C

解析:該題說的是：用于實驗的老鼠最終全部死于肺癌。文章中并沒有提到老鼠最后的生死。因此選C

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