A line that serves as a frame of reference for measurement in a chart is a(n) ________

Which of the following allows the linking together of two or more interdependent tables in a meaningful way?

(A) ANSI (B) foreign keys (C) duplicate entries in a single field (D) null values

Which of the following are not shown on an activity diagram?

A) classes B) events C) decisions that are made D) sequence of activities