What is a collaboration-oriented technology on the web that allows anyone to update posted information?
a. facebook
b. twitter
c. wiki
d. youtube

Write a method so that the main() code below can be replaced by the simpler code that calls method original main(): public class calcmiles { public static void main(string [] args) { double milesperhour; double minutestraveled; double hourstraveled; double milestraveled; milesprhour = scnr.nextdouble(); minutestraveled = scnr.nextdouble(); hourstraveled = minutestraveled / 60.0; milestraveled = hourstraveled * milesperhour; system.out.println("miles: " + milestraveled); } }

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)?

Scientists have changed the model of the atom as they have gathered new evidence. one of the atomic models is shown below. what experimental evidence led to the development of this atomic model from the one before it? a few of the positive particles aimed at a gold foil seemed to bounce back. the colors of light emitted from heated atoms had very specific energies. experiments with water vapor showed that elements combine in specific proportions. cathode rays were bent in the same way whenever a magnet was brought near them.