Berachos 6b

Maybe this will seem very simple to some of you, but I didn't understand what the following Rashi was saying, until today. The gemara says: "R' Yochanan says: When Hashem comes into a shul and doesn't find ten people there, he immediately gets angry, as it says, 'Why did I come and there is no man, I called out and there is no answer.' " Rashi says: "And there is no answer. The amount of people who could answer a Davar Kedusha."
Rashi is answering this question: What is the proof from the pasuk that Hashem gets angry if there aren't ten people in the shul, maybe the pasuk is talking about when there isn't anyone in the shul, and only then does Hashem get angry! To that Rashi answers that the words, "There is no answer," mean there is no tzibbur of ten to answer to a Davar Kedusha, like Kaddish or Borchu, even though there may be some people in the shul.