机侧汽温超过()℃,应立即打闸停机,锅炉灭火,故障处理后再启动恢复。
参考答案:567
—Oh, Mrs. King, your necklace looks nice. Is it new?
—No, I _____ it for two years. [ ]
A. had
B. have had
C. bought
D. have bought
齿轮泵试车的注意事项是什么?