《儒林外史》中的正面人物，作者以为可作儒林典范的是杜少卿。
参考答案：错
David had prepared carefully for the chemistry exam, as he wanted to be sure of passing it at the first _____.
A．experiment
B．intention
C．aim
D．attempt
局扇停止运转后恢复送风时，要采取哪些安全措施？
