What does the logic symbol     ::      mean?

Which one of the following statements is FALSE, in regard to analogical arguments?

Let:        R = The Ravens will make it to the Super Bowl. T = The Texans will make it to the Super Bowl.       and H = The team from Houston will make it to the Super Bowl. (And assume that the Texans are from Houston.) If so, then which one of the following is the COMPLETE and MOST ACCURATE translation of this statement: “The Texans will make it to the Super Bowl if and only if the team from Houston will make it to the Super Bowl.”

When he got the commission for the Eddystone Lighthouse, Smeaton undertook several experiments. Identify the one statement that was not true of Smeaton’s experiments.

What breathing instructions should be given when performing an AP shoulder in internal and external rotation?

How should the hand be placed for the PA projection of the wrist?

A: B: C: D: E: F:

List one evaluation criteria to determine the appropriate kVp was used on a portable CXR. 

What is the appropriate kVp range for this examination?

What are the appropriate breathing instructions for this examination?