*Question*
If cattle can have a negative impact on the environment, then what can have a negative impact on the environment? Answer choices: - toxins - trees - Cars - cattle - tar - nutrients - h2o - coal
**Answer**
cattle

*Question*
If viruses can infect and destroy helper T cells, then what can infect and destroy helper T cells? Answer choices: - Q cells - Cooking - bacteria - red blood cells - a-a gradients - parasites - viruses - cigarettes
**Answer**
viruses

*Question*
If some invertebrates are protected by a hard shell on their backs, then what are some invertebrates protected by on their backs? Answer choices: - fur - parasites - barnacles - shells - coats - bones - bushes - Epidermis
**Answer**
shells

*Question*
If cold fronts cause tornadoes, then what causes tornadoes? Answer choices: - Electrical energy - scattered light - hypothyroidism - Time and energy - harmful substances - Cold fronts. - Tropical - heat energy
**Answer**
Cold fronts.