The _device provides a means of communication between a computer and outer world.

If the polar bear were taken out of the food chain what would happen to the seal population the seal population would diminish the seal population would grow dramatically the seal population would stay the same the seal population would decrease slightly

The "instance" relationship shows that something is an object of a

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)?