A
Coronaviruses are a large group of viruses. They consist of a core of genetic material(遗传物质) surrounded by an envelope with protein spikes(蛋白棘突). This gives it the appearance of a crown. Crown in Latin is called “corona” and that’s how these viruses get their name. In this text, we’ll take a quick look at what’s currently known about the virus.
Covid-2019
The 2019 Novel Coronavirus, first reported December in Wuhan, central China's Hubei Province, has quickly spread across the country and around the world. It initially occurred in a group of people with pneumonia（肺炎） who’d been associated with a seafood and live animal market in the city of Wuhan.
Intermediate hosts: The Covid-2019 may originate in bats, a team led by renowned Chinese virologist Shi Zhengli said earlier, while the intermediary host remains unknown.
Incubation period(潜伏期): usually 1-14 days.
Infection: Virus may spread before symptoms show.
SARS-CoV
The Severe Acute Respiratory Syndrome (SARS) coronavirus was first identified in China in 2003 .
Intermediate hosts: Bats are the original host. Civet cats serve as an important intermediary that carries virus from the winged mammal to humans.
Incubation period: 2-7 days.
Infection: Virus spread after symptoms show.
MERS-CoV
The Middle East Respiratory Syndrome (MERS中东呼吸综合征) coronavirus was first identified in Saudi Arabia in 2012.
Intermediate hosts: MERS-CoV was travelled from dromedary camel to humans.
Incubation period: 2-14 days.
Infection: Virus may spread before symptoms show.
21. What might be the intermediate hosts of the Covid-2019?
A. Bats. B. Mosquitoes C. Camel. D. Unknown yet.
22.Which kind of coronaviruses spreads after symptoms appear?
A. The Covid-2019. B. MERS-CoV. C. SARS-CoV. D. All Coronaviruses.
23. What can we learn about coronaviruses ?
A. Bats are to blame for the outbreak of all the three coronaviruses.
B. Mers-Cov were first identified in China.
C. SARS-Cov has a longer incubation period than Mers-cov.
D. The Covid-2019, SARS-CoV and MERS-CoV are all listed as coronaviruses.
