题目

 He was in hospital for six months. He felt as if he was _____ from the outside world. A. cut out            B. cut off           C. cut up         D. cut through 答案：B如下图所示实验室制取酚醛树脂的装置，按要求填写下列空白：（1）长玻璃管的作用除导气连通外还有               。（2）此反应需水浴加热，为什么不用温度计控制水浴温度？                                                 （3）写出实验室制取酚醛树脂的化学方程式(有机物用结构简式)：                                            。