73-200潜孔钻机接卸钻杆时,钻杆下部是靠()支撑的。
参考答案:托杆器
用所给词的正确形式填空。
1. Your father looks very (health).
2. You must look after (you).
3. (read) in bed is bad for your eyes.
4. He (be) ill yesterday.
5. I stayed away from school for (little) than a week last term.
6. You (be) not here yesterday morning.
7. Doing eye (exercise) is good for your eyes.
8. Do you like eating (vegetable)?
9. She was away for (many) than three weeks last year.
10. I (usual) get to school very early.
有一个“12V 6W”的小灯泡,如果接在36V的电源并要求能使其正常发光,必须______联一个______Ω的电阻,这个电阻消耗的电功率是______W.