Experts hope an experimental drug can be as effective against the novel coronavirus in people as it has been on cells in a controlled lab environment .
   The US drug，remdesivir（瑞德西韋），began clinical trials on patients in Wuhan，Hubei province，on Wednesday.Other medications，including chloroquine，arbidol and darunavir have also recently been found capable of arresting viral growth in lab cells，but like remdesivir they require more clinical trials to confirm their safety and potency on humans.
   The Phase Ⅲ trials for remdesivir have been approved by China's National Medical Products Administration and will be conducted by the China-Japan Friendship Hospital in Beijing and the Chinese Academy of Medical Sciences on patients at the Wuhan Jinyintan Hospital.
   A total of 761 patients will participate in two trials-one trial to assess the drug's potency on 308 cases with mild or moderate infection，and the other on 453 severely infected patients，Cao Bin，head of the clinical trial and vice-president of the friendship hospital ，said on Wednesday .
   Cao said studies have shown remdesivir is effective in inhibiting the growth of the novel coronavirus in titro（在生物體外），meaning the procedure was done on cells in a controlled environment outside of a living organism，typically in a petri dish or test tube.
   But the drug has yet to show convincing clinical evidence that it can translate its positive in vitro results into actual human patients.Hence，it will require rigorous clinical testing，Cao said.
   A 35-year-old patient from the United States infected with the virus was reported seeing noticeable improvement with no obvious side effects after taking the drug，according to the New England Journal of Medicine Gilead Sciences，the maker of remdesivir，said in a recent statement that it has been working with government agencies on the novel coronavirus response efforts.
   However，the company stressed that remdesivir is an experimental medicine that has only been used in a handful of patients on compassionate grounds，"so we do not have an appropriately robust understanding of the effect of this drug to warrant broad use at this time".

（1）Why does the US drug，remdesivir，began clinical trials？

B

B

A．To replace the traditional medicine.
B．To confirm their safety and potency on humans.
C．To show whether remdesivir is effective in inhibiting the growth of the novel coronavirus in vitro.
D．To see how it takes effect.
（2）Which statement is true according to the passage？

B

B

A．After taking the drug，a 35-year-old patient was infected with the virus.
B．Doctors had seen apparent success treating a 35-year-old patient infected with the virus
C．Remdesivir can cure those who are infected with the novel coronavirus
D．Chinese Hospital does The Phase Ⅲ trials independently.
（3）What's the author's attitude towards the clinical trial of remdesivir？

C

C

A．Negative.
B．Critical.
C．Positive.
D．Gloomy.