If the key cells involved in the immune response produce antibodies, then the cells that produce antibodies are key in what system? Answer choices: - health - T cells - vision - humans - macrophages - B cells - disease - immune
immune

If physical changes cause solids to form, then what causes solids to form? Answer choices: - Physical weathering - an external framework - Physical changes - adding sand - adding mud - heating liquids - adding water - A solid geometric shape
Physical changes

Q: If afirecracker converts chemical energy into audible waves, then what can convert chemical energy into audible waves? Answer choices: - a flashlight - electrically - animals - a firecracker - power stations - sensory neurons - x-ray - electrical light
A: a firecracker

Question: If irradiation can be used to extend the shelf life of food, then what can be used to extend the shelf life of food? Answer choices: - Cooking - Enzymes - rays or beams - irradiation - leaving food at room temperature - Dehydration - eating food - grinding food
Answer: irradiation

*Question*
If cells secrete acids and bases to maintain the proper pH for catalysts to work, then catalysts require proper what to work? Answer choices: - DNA - pH - pan - RNA - elevation - time of day - gas - humidity
**Answer**
pH

(Q).
If minerals are excreted through the urinary system, then what is excreted through the urinary system? Answer choices: - glucose - matter - liquid - CO 2 - sodium - potash - sugar - water
(A).
water