The correct answers are The suspect has been sitting at the corner table since noon. and He has been drinking the same cup of coffee for two hours.

The Present Perfect Continuous is formed with Subject + have/has + been + verb-ing.

"He has being reading" is incorrect because the auxiliary verb must be been, not being.

"He has been waited" is incorrect because it uses the past participle (waited) instead of the present participle (waiting). Additionally, we use for (not since) with a duration of time like "a long time."