How are pathogens able to get past the body’s first line of defence?

Providing immunity by injecting the body with a weakened form a pathogen is known as

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.

Some scientists argue that global warming is related to buming fossil fuels to produce energy o increased use of fertilizers loss of forested areas a of the above