air/water blasting media (35 percent); water jet cutting (30 percent), which used concentrated, high-pressure water jets for precision cutting of metals; water filtration (15 percent);
Has and have are two forms of the infinitive to have Has is used for he, she and it, and generally speaking third person singular. (eg Richard has a lot of friends) Have is used for all other case...
Using " Has " is referred a past tense. Such as: He has taken the garbage out already. Using " Is " for example is referred a Present tense. Such as: He is taking out the garbage.