What is a question about this article? If the question is unanswerable, say "unanswerable".

According to Sun Jiadong, the chief designer of the navigation system, "Many organizations have been using our system for a while, and they like it very much."

What did Sun Jiadong have to say about the BeiDou navigation system?
"Many organizations have been using our system for a while, and they like it very much."