题目

如图所示装置可用于测定空气中氧气的含量。下列说法错误的是（） A . 实验前要检查装置的气密性 B . 集气瓶中液面先上升后下降 C . 用激光笔点燃白磷可防止测量数据不准确 D . 实验成功的标志为集气瓶中水面最终停在1处 答案：B________ amazed me most was that the boy who had lost both arms in an accident could handle a pen with his feet. [     ]A．That  B．ItC．Which  D．What