n. 无线电a. 无线的, 无线电的【电】 无线

• 与put连用的介词很多，一般来讲on与off是一对相反的意 义的介词，如： turn on (打开)，turn off(关上)，穿衣服是put on，但脱衣服却只能用take off,而put o ff是推迟、使某人下车、关掉之意，如： They put off the exam because t he national holiday. (因国家假日而推迟考期。)Could you put me off at the Town Ha ll. (请在市政厅让我下车。)Please put off the wireless before you leave. (走之前 请关掉无线电。)
  
  ［误］ She put off her red dress and put on the green one.
  
  ［正］ She took off her red dress and put on the green on e.
  
  ［析］ 与put连用的介词很多，一般来讲on与off是一对相反的意 义的介词，如： turn on (打开)，turn off(关上)，穿衣服是put on，但脱衣服却只能用take off,而put o ff是推迟、使某人下车、关掉之意，如： They put off the exam because t he national holiday. (因国家假日而推迟考期。)Could you put me off at the Town Ha ll. (请在市政厅让我下车。)Please put off the wireless before you leave. (走之前 请关掉无线电。)
  

radio/radium/radiate/radiation/radio-active/wireless
记忆：
1. radio　[ 5reidiEu ]　n. 无线电通信，收音机 To listen to the English programs on the radio is very helpful in improving our English. 听电台的英语节目对提高我们的英语水平很有帮助。
2. radium [ 5reidjEm ]　音“镭”，具有放射性，　n. 镭 It’s Madam Curie who discovered radium. 是居里夫人发现的镭。
3. radiate [ 5reidieit ]　vt. 放射, 辐射 Heat radiated from the stove warmed the whole room 从炉子里车身出来的热温暖了整个房间。
4. radiation [ 7reidi5eiFEn]　n. 放射, 辐射 The nuclear radiation caused severe pollution. 核辐射引起了严重的污染。
5. radio-acitve 　adj. 放射性的 The soil there proved to be radio-active. 那儿的土壤被证明有放射性。
6. ray [ rei ]　n. 光线，射线 The morning ray came through the window, making the room full of warmth. 晨光从窗口进来，使房间里充满了温暖。
7. wireless [ 5waiElis ]　adj. 无线电的，无线的 Our company is devoted to wireless communication我们的公司致力于无线电通讯。
另类阅读：
Radios are sometime called “wireless,” for they pick up messages without any wires. Radios may have something to do with radiation, but it’s not radio-active at all. No harmful rays radiate from them.