Corona Viruses are a group of viruses. They consist of a core of __________ sounded by an envelope with protein spikes (蛋白质冠状物) . This gives it appearance of a __________, which is called corona in Latin. (28’’)
【简答题】用 a, an, the, some, any填空。 1. I have ______ alarm clock. 2. The books are on______desk. 3. Look at______plant. It's very nice. 4. I need______ID card. 5. I can see______ photo on the wall. 6. C...