virus可数，复数是viruses
This means scientists cannot monitor the virus 's evolution .
这意味着科学家不能监测病毒的进化。
Then ， with their typical generosity ， they give the virus to humans .
随后，蚊子用它们典型的传染方式将病毒感染到人类身上。
Later virus and malaria will be added .
之后病毒和疟疾会被加入。
And the virus might spread globally .
而且这一病毒也许会在全球蔓延。
virus表示第一个释义时，既可以作可数名词，也可以作不可数名词，剩余释义均作可数名词。
1、 a very small living thing that causes infectious illnesses病毒
例如：children infected with the AIDS virus
感染艾滋病病毒的儿童
a virus infection
病毒感染
2、 a set of instructions secretly put onto a computer or computer program， which gain information. When a computer that has a virus makes a connection with another computer， for example by email， the virus can make copies of itself and move to the other computer.计算机病毒
3、 a program that sends a large number of annoying messages to many people's mobile phones in an uncontrolled way手机的短信病毒
