On one summer night, Henry was sleeping in his room when suddenly he woke up and sensed that something unusual. He looked out of the window and finding a store nearby on the street was in fire. He immediately shouts at the top of his voice “Fire! Fire! Help!” He phoned 119 at once and then went out to put out fire. but it was very big a fire that he couldn’t put it out by himself. Lucky enough, a lot of neighbours came out and soon firefighters arrived. The fire was finally put out and when the firefighters praised Henry his quick action, he smiled, feeling very pleasing.

如何用煤油检查推力瓦块钨金面裂纹？