In a table, pressing the ____ key(s) moves the insertion point to the previous cell.

When is an array based implementation of the ADT stack not a better choice?

a. the stack can be large, but often is not b. the stack does not exceed the fixed size of the array c. the stack is most always right around 80 characters d. the stack represents the number of students in a typical class

State which of the following schedules are serializable.

a. r1(x) r2(y) r1(z ) r3(z ) r2(x) r1(y) b. r1(x) w2(y) r1(z ) r3(z ) w2(x) r1(y) c. r1(x) w2(y) r1(z ) r3(z ) w1(x) r2(y) d. r1(x) r2(y) r1(z ) r3(z ) w1(x) w2(y) e. w1(x) r2(y) r1(z ) r3(z ) r1(x) w2(y)