题目内容：

    Zhong Nanshan, an 84-year-old doctor, is the public face of China's effort to control a new kind of virus（病毒）. He became famous 17 years ago for “ daring to speak” in the fight against SARS. Zhong has been named to head of a high-level expert team organized by National Health Commission to research the new virus.

On January 20th, Zhong reported that the new virus could spread from person to person. Also, President Xi Jinping called for strong action to stop the spread of the new virus on that day.

The next day, Zhong Nanshan told reporters in Guangzhou that the government had been truthful about reporting cases of COVID-19. He also said the government was trying to deal with the outbreak. On January 23 rd, officials closed off all transportation to and from Wuhan. It was said that Zhong had pushed for the move.

In 2003, the situation was very different. The officials were fearful of telling the truth about the SARS outbreak. At the time, Zhong talked to reporters about the virus. A video in 2003 showed him telling reporters little was then understood about it. No one knew how it was spreading or the correct treatment. In a 2016 television program by CCTV, Zhong remembered he was asked if the SARS outbreak was under control. He said,“ I couldn't help myself. I said it's not under control at all.” The program praised Zhong for “daring to speak”.

1.When did President Xi Jinping call for strong action to stop the spread of the new virus?

A.On January 21st. B.On January 20th.

C.On February 21st. D.On February 23rd.

2.What is Zhong Nanshan's attitude to the government according to Paragraph 3?

A.Positive. B.Serious. C.Careful. D.Worried.

3.What does the underlined word "it” in the last paragraph refer to?

A.The new virus. B.SARS.

C.The video. D.The television program.

4.What's the main idea of the passage?

A.China is trying to call for strong action to control a new kind of virus.

B.Zhong Nanshan explains how he fought against SARS in 2003.

C.A famous SARS fighter dares to fight against the new virus again.

D.A new kind of virus has been spread from person to person around the world.