Fill in the blanks to complete the sentences. Viruses are unable to move by themselves, so they need to be...

Fill in the blanks to complete the sentences.
Viruses are unable to move by themselves, so they need to be __________ to reach their destination.
For example, if a __________ carrying a virus bites a person, that person can become __________. It could also occur if a person breathes in __________ air or comes in contact with __________ fluids containing a virus.