题目

—I have failed in the driving test again. I ______ hard on it but …—Never say die. In fact, the new rules are too difficult but you are making progress. A . work B . worked C . have been worked D . had been working 答案：D一定条件下，0.3mol X（g）与0.3mol Y（g）在体积为1L的密闭容器中发生反应：X（g）+3Y（g）?2Z（g），下列示意图可能成立的是（　　） A、B、C、D、