题目内容：

Scientists around the world are striving for effective detection of cancer in the early stages,which is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body,and a Chinese scientist may have found a quick way of knowing whether malignant tumors（恶性肿瘤）exist in a patient's body,with just one drop of blood.

Malignant tumors in early phases can be cured.However,it's extremely difficult to be aware of cancer in its early stages,as patients don't show obvious symptoms and thus it can only be found in its later stages,which is already too late,so to detect cancer early remains a global challenge for scientists.

Back in 1989,scientists have found a kind of heat shock proteins (HSP),named Hsp90α,which existed in human bodies and can be used as a cancer biomarker detection kit.Scientists around the globe have been working on it since then,and more than 10,000 journals have been published on accredited magazines,yet no one has actually turned their research results into medical products.

However,Luo Yongzhang and his team in Tsinghua University's School of Life Sciences in Beijing seemed to have cracked the code,after working on the problem since 2009.The team has produced an artificial Hsp90α protein for clinical use that gains structural stability by regrouping proteins.The test kit can diagnose multiple kinds of cancer by analyzing a drop of human blood.This means they are able to "create" the protein,in any quantity,and at any time they wish to.

The kit has since been used in clinical trials involving 2,347 patients at eight hospitals in China.It was the first clinical trial in the world to test if the protein could be a useful tumor biomarker for lung cancer,and it succeeded. Now,the kit has been approved to enter the Chinese and European markets,24 years after Hsp90α was discovered.

1.Why is cancer hard to cure?

A. Malignant tumors are found too late.

B. Malignant tumors spread too quickly.

C. Its symptoms are shown in early stages.

D. No proper treatment can be applied to it.

2.What do we learn about Hsp90α from Paragraph 3?

A. It was created by scientists in 1989.

B. All magazines have covered the topic.

C. There has been a medical product about it.

D. It can serve as a cancer detection approach.

3.How does the Chinese kit diagnose cancer?

A. By regrouping proteins.

B. By cracking cancer’s code.

C. By breaking down one drop of blood.

D. By producing an artificial Hsp90α protein.

4.It can be inferred that a European with lung cancer in early phases .

A. can’t be cured in the end

B. can be diagnosed with it in time

C. has to be examined in China

D. expects the kit to come into the market