1. (2021高二上·湛江期中) 阅读理解

World Health Organization (WHO) chief scientist Soumya Swaminathan said Monday that herd immunity to coronavirus would not be achieved in 2021, despite the growing availability of vaccines (疫苗产量).

Factors that delay herd immunity include limited access to vaccines in developing countries, skepticism (怀疑) over vaccination, and the potential for virus mutations (变异), according to health experts.

A growing number of countries around the world, including the United States, the United Kingdom, Singapore, Germany and other European Union countries, are in the first stages of mass-vaccination campaigns.

Herd immunity occurs when enough people in a population have immunity to an infection(传染) so that it prevents the disease from spreading.

"We are not going to achieve any levels of population immunity or herd immunity in 2021," Swaminathan said, while emphasizing that measures like physical distancing, hand washing and mask wearing continue to be necessary in controlling COVID's spread for the rest of the year.

However, Swaminathan praised the "incredible progress" made by vaccine researchers to develop several safe and effective vaccines at unprecedented (空前的) speed. Countries are currently administering vaccines developed by BioNTech-Pfizer, Oxford University AstraZeneca and Moderna.

"The vaccines are going to come," she said. "They are going to go to all countries, but meanwhile we mustn't forget that there are measures that work," she added, referring to hygiene (卫生) and social distancing.

"We won't get back to normal quickly," Dale Fisher, chairman of the WHO's Outbreak Alert and Response Network, told a conference hosted by Reuters news agency. "We know we need to get to herd immunity and we need that in a majority of countries, but we are not going to see that in 2021," Fisher said. "There might be some countries that might achieve it but even then that will not create normal especially in terms of border controls," he added.

1. （1） Which of the following are NOT the factors that delay herd immunity?

   A . People are skeptical about vaccination. B . Access to vaccines in developing countries is limited. C . A growing number of countries begin mass-vaccination campaigns. D . Virus mutations are likely to happen.
3. （2） As for the first stages of mass-vaccination campaigns, which country is NOT mentioned in the passage?

   A . Vietnam B . Germany C . Singapore D . the United Kingdom
5. （3） What can we learn from what Fisher said?

   A . In many countries in 2021, people will live a normal life in terms of border controls. B . If some countries might achieve herd immunity, people will live a ‘normal' life. C . In terms of good border controls, we can achieve herd immunity. D . There maybe a long way to get to herd immunity all over the world.
7. （4） What is the attitude of Swaminathan to the progress of vaccine development?

   A . Positive B . negative C . unclear D . neutral