Question

snake scientists. it is their only job, and it is a dangerous one.
venomous snakes, like this viper, have special teeth called fangs. the fangs contain venom
milking a snake takes careful work. scientists dont just jam their hands in the snakes mouth. a snake will bite anything that is pushed into its fangs!
what does jam mean in this passage?
to hold tightly
to feed an animal
to force something in
to protect something

Explanation:

The context mentions that scientists don't just "jam" their hands in the snake's mouth and that a snake will bite anything pushed into its fangs. The word "pushed" implies forcing something in.

Answer:

to force something in.