所托物品要避开自己的鼻口部位。端托中需要讲话时，应将托盘托至身体的左外侧，避开自己的正前位。
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The word corona in Latin means________.
A. spiked
B. jagged
C. crown
D. protein
Although there are hundreds of coronaviruses, only ________currently infect humans.
A. ten
B. seven
C. five
D. four
Why do we need a new flu vaccine every year?
A. Influenza mutates quickly and new strains result
B. Our bodies rid themselves of the vaccine yearly
C. When it gets warm outside, vaccines do not work anymore
D. Cooler temps often cause vaccines to mutate and not be effective
Corona viruses are a bit different from other RNA viruses. How?
A. They are quite large with many genes.
B. They are usually much more stable.
C. They often have a faster mutation rate.
D. A and B are both answers.
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