Please help me Select the correct answer.

Which is the most important procedure that a search engine should perform to be highly efficient?

А. query prediction

B. indexing

C. any word search

D. preparing quality lists

Which of the following natural processes is most likely to support the formation of an underwater sinkhole? a pollution buildup from deposited minerals b limestone cave collapsing due to changes in sea level c erosion of large amounts of sand moved by ocean waves d oxidation of rock formed by chemical weathering

Sulfuric acid is a polyprotic acid. write balanced chemical equations for the sequence of reactions that sulfuric acid can undergo when it's dissolved in water.

Condensation happens when water vapor cools. true or false? ?