.,A1P.(B is used as a verb when it is pronounced in the first tone. When it is attached to another character to form a noun, it should be pronounced in the fourth tone, as in: .,A1P.(B .,A+G.(B jiao4shi4 classroom); .,A1P.(B .,A1B.(B jiao4shou4 (professor); .,A1P.(B .,A..(Bv jiao4shi1 (teacher).