*Question*
Erosion of soil has a negative impact on the environment, and cattle can cause soil erosion. Given these facts, what can have a negative impact on the environment among the following options: - toxins - trees - Cars - cattle - tar - nutrients - h2o - coal
**Answer**
cattle

*Question*
HIV infects and destroys helper T cells, and lets Meet the HIV HIV is a new virus. Given these facts, what can infect and destroy helper T cells among the following options: - Q cells - Cooking - bacteria - red blood cells - a-a gradients - parasites - viruses - cigarettes
**Answer**
viruses

*Question*
Mollusks are invertebrates such as the common snail, and snails are protected by a hard shell on their backs. Given these facts, what are some invertebrates protected by on their backs among the following options: - fur - parasites - barnacles - shells - coats - bones - bushes - Epidermis
**Answer**
shells

*Question*
Cold fronts cause thunderstorms as they pass by, and thunderstorms Thunderstorms give birth to tornadoes. Given these facts, what causes tornadoes? among the following options: - Electrical energy - scattered light - hypothyroidism - Time and energy - harmful substances - Cold fronts. - Tropical - heat energy
**Answer**
Cold fronts.