For the second time in a month, the young woman in the dark jacket walked out of her South Austin house and learned her childhood friend had been shot.



The first time, in late January, her friend was shot in the foot in the 5200 block of West Congress Parkway where they have lived all their lives. The bullet was still lodged inside when he was shot again around 9:30 p.m. Tuesday while driving to a store.



He was hit in the side and thigh and was reported stable at Mount Sinai Hospital.



"Two times in a month?" the woman said, shaking as she smoked a cigarette. "What’s the problem?"



This time, her friend had been shot a few blocks away and managed to drive back to his house. Neighbors found himsensor which includes a first diffusion rate controlling passage, a first internal space communicated with the first diffusion rate controlling passage, a second diffusion rate controlling passage, a second internal space communicated with the second diffusion rate controlling passage, a third diffusion rate controlling passage, a third internal space communicated with the third diffusion rate controlling passage, and an air introducing duct; wherein the first diffusion rate controlling passage is a passage provided for introducing an object gas containing an object component including a sort of combined oxygen from an external gas existing space to the first internal space under a predetermined diffusion resistance; wherein the first internal space is provided for effecting the combustion of some combustible gases, and is provided with a first electro-chemical pump for