题目内容：

A cheap drug that can stop bleeding in people recently injured in an accident could potentially save the lives of tens of thousands worldwide, a new study says.

Researchers studied the effects of tranexamic acid （凝血酸）, or TXA, in more than 10,000 injured people in 40 countries who received the drug within 8 hours of being injured. The study was published in the medical journal Lancet. Doctors found that patients who got TXA had a 15percent lower chance of dying from hemorrhage than those who didn’t get it . They also had a 10 percent lower chance of dying from any other cause, including organ failure and a head injury. The study was paid for by the British government.

The drug is commonly used in wealthy countries during elective surgeries(外科手术) to stop bleeding , but isn’t used for accident victims. TXA is off-patent and made by many companies. It costs about $4.5 per gram, and a typical dose is two grams. It is usually given via an injection（注射） and would be relatively easy to introduce, even in poor countries, experts said.

Previous tests of the drug regarded its use in elective surgeries, such as heart operations, but this was the first study to test the drug on accident victims. Doctors were worried it might increase side effects such as blood clots （凝块）in the heart and lungs, strokes, or heart attacks. There was no evidence of that in the Lancet study, though the authors said it was possible they might have missed some of these incidents.

For people between 5 and 45, accidents are the second leading cause of death worldwide after AIDS, and about 600,000 injured patients bleed to death every year. Experts estimated that if TXA were readily available, between 70,000 and 100,000 lives a year could be saved. Though the drug wasn’t tested on children , experts said it would almost certainly work with them as well.

1.The underlined word” hemorrhage” in Paragraph 2 probably means ________

A．serious illness

B．heart disease

C．heavy bleeding

D．lack of drug

2.What can we learn about TXA from the passage?

A．It can only be made in England	B．It was only used in operations before
C．It is a patented drug	D．It is mainly used in poor countries

3.Doctors were worried about using TXA because ________

A．a lot of patients died unexpectedly after using it

B．it has no treatment effect on patients

C．it can cause blood clots or stroke

D．they hadn’t used it on accident victims before

4. What do we know from the last paragraph?

A．It is a pity that TXA wasn’t widely used on injured patients before

B．Tests have proved that TXA can be used on children

C．People between 5 and 45 should be injected with TXA every year

D．Accidents are the first leading cause of death worldwide.