焊条电弧焊立焊操作时,弧长应()焊条直径,电弧过长易产生气孔。
A.大于
B.小于
C.2倍于
D.3倍于
参考答案:B
根据所给的汉语提示用其适当的形式填空。
1. The baby was already __ (醒着的)
2. The machine is in _ _ .(运动)
3. Don’t walk on the street in the ___ of the night. It’s too dangerous. (中间)
4. True ___ is worth more than money. (友谊)
5. He threw a ___ at the dog. (石头)
6. Haiku follows a ___ (模式)
7. There are two ___ in "window" .(音节)
8. The rain was heavily ___ on the window.(飞溅)
空气在喷气发动机的压气机中的流动可以看作:().
A.绝热压缩过程
B.绝热膨胀过程
C.等容加热过程
D.等压加热过程