题目

选编（十七） Several years ago, while attending a communication course, I experienced a most unusual process. The instructor asked us to list ___1___ in our past that we felt ___2___ of, regretted, or incomplete about and read our lists aloud. This seemed like a very ___3___ process, but there’ s always some ___4___soul in the crowd who will volunteer. The instructor then ___5___ that we find ways to ___6___ people, or take some action to right any wrong doings. I was seriously wondering how this could ever ___7___ my communication. Then the man next to me raised his hand and volunteer下列气体中，既有可燃性又有还原性的是                          （    ） A．CO            B．O2           C．N2          D．He