What always happens when two objects interact?

Poland had achieved self government and can enjoy its since the collapse of the soviet union a: autonomy b: ingenuity c: feminismd: genocide

Which of the following characterize the historical move toward urbanization? i. increase in pollution ii. increase in frequency of natural disasters iii. increase in incidence of infectious disease a. i b. ii c. i and ii d. i and iii e. i, ii and iii

Ineed asap! i need to finish a lab report but i don't understand this if starch +saliva treated with vinegar(acid ) what does indicate?