求翻译：仪器后盖有三个接管嘴，它们是：（1）氧气进气接管嘴（进氧嘴②）、（2）氧气出气接管嘴（出氧嘴③）、（3）混合燃气进气接管嘴（燃气嘴①）是什么意思？

There are three instruments cover over the mouth, they are: (1) into the air over the mouth of oxygen (oxygen into the mouth ②), (2) to take over the oxygen outlet mouth (oxygen out of the mouth ③), (3) mixed gas into the air over the mouth ( Gas nozzle ①)

There are 3 covers apparatus after a receiver's mouth, and they are the following: ( 1) oxygen into oxygen gas took over his mouth to mouth ( 2 ), ( 2) oxygen (oxygen breathed his mouth take over his mouth, ( 3) 3) mixed gas inlet receiver nozzle (gas nozzle 1)

The instrument top plate has three to meet the nose, they are: (1) oxygen air admission control mouth (enters the oxygen mouth②) (2) oxygen air vent control mouth (oxygen mouth③) (3) mix fuel gas air admission control mouth (burns the air faucet①)

Instrument rear cover has three Union, they are: (1) oxygen inlet Union (into oxygen body ②), (2) oxygen vented Union (③ oxygen mouth), (3) and mixed gas inlet Union (gas nozzle ①)

There are three instruments cover over the mouth, they are: (1) into the air over the mouth of oxygen (oxygen into the mouth ②), (2) to take over the oxygen outlet mouth (oxygen out of the mouth ③), (3) mixed gas into the air over the mouth ( Gas nozzle ①)