Context: On July 17, 2012, the CRTC approved the shut down of CBC's analogue transmitters, noting that "while the Commission has the discretion to refuse to revoke broadcasting licences, even on application from a licensee, it cannot direct the CBC or any other broadcaster to continue to operate its stations and transmitters." On July 31, 2012, at around 11:59 p.m. in each time zone, the remaining 620 analogue transmitters were shut down, leaving the network with 27 digital television transmitters across the country, and some transmitters operated by some affiliated stations.

Question: On what date did the CTRC approve the shut down of CBC's analogue transmitters?
Answer: July 17, 2012

Question: On what date were CBC's remaining analogue transmitters shut down?
Answer: July 31, 2012

Question: How many analogue transmitters were shut down on July 31, 2012?
Answer: 620

Question: When did the CRTC order the shutdown of the analogue transmitters?
Answer: Unanswerable

Question: When did the CRTC shut down the 620 analogue transmitters?
Answer: Unanswerable

Question: How many transmitters did the CRTC think were appropriate to leave operable?
Answer: Unanswerable

Question: What did the director of the CRTC regret not being able to do?
Answer: Unanswerable