Which invention made it possible to have an entire computer on a single circuit board

Which action is good business etiquette? a. switching your cell phone off before you enter a meeting b. keeping your cell phone on low volume before you enter a meeting c. setting a pleasant ring tone on your cell phone before you enter a meeting d. setting a standard ringtone on your cell phone before you enter a meeting

Which best explains why a digital leader would join a society specializing in technology

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)?