While slow motions are characteristic in tai chi, several styles (including the three most popular: Yang, Wu, and Chen) have additional, faster-paced forms. Some traditional schools teach tuishou ("pushing hands") pair exercises and martial applications of various postures (taolu). The first form that most students learn is called "dajia" (or "alleycat"). This is a generic term for any one of the eight basic forms of tai chi, although it usually refers to the first one taught. The second form that many schools teach is called "xiangju" (or "dragon claw"). This form is similar to dajia but includes some special moves such as swinging arms back and forth like a pendulum or slapping the floor with palms facing up in front of you. Some schools also teach meng (or "internal skill") and hua (or "external skill") versions of each form. Meng means performing all of the movements without touching the ground while hua means using your body weight to perform some of the movements. These forms are practiced to sharpen awareness and focus the mind as well as build strength and flexibility. Students learn proper breathing techniques and how to use them to their advantage during combat situations or even just when they feel threatened.