In a switch statement: 1. A break is required after each case.
2. Multiple actions in a case do not need to be enclosed in braces.
3. A default case is required.
4. A break is required after the default case.

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)?

Barbara is interested in pursuing a career in the science and math pathway. which qualifications will her reach that goal? a.an advanced knowledge of physics and math b.an advanced knowledge of engineering and math c. an advanced knowledge of physics and robotics an d. advanced knowledge of machinery and math

Asecurity policy is a a. set of guidlines b. set of transmission protocols c. written document d. set of rules based on standards and guidelines