Which inventions in printing do you believe had the biggest impact on society and why?

What kind of software users of all skill levels create web pages that include graphics, video, audio, animation, and other special effects? website authoring website software website publishing website editing

Three out of five seniors remain undecided about a college major at the end of their senior year.

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?