*Question*
If lead causes harm to living things, then which causes harm to living things? Answer choices: - rabies - Oxygen - deadly - HIV - Lead - Carbon - Nitrogen - toxins
**Answer**
Lead

*Question*
If severe droughts may cause a bottleneck effect, then severe droughts may cause? Answer choices: - evolution - population growth - forest is destroyed - species variation - major threat to health - Dehydration - the ground shaking - a bottleneck effect
**Answer**
a bottleneck effect

*Question*
If weathering is the breakdown of rock, then _is the breakdown of rock.? Answer choices: - Weathering - mechanical - salinity - heat energy - dangerous - cycles - calcite - started
**Answer**
Weathering

*Question*
If electricity is used to see in the dark, then what is used to see in the dark? Answer choices: - steak - Eye patch - electricity - energy barrier - photons - energy - our nearest star - Wishful thinking
**Answer**
electricity