填them.my teacher or my classmates也就是任意,同时是说见到他们谁都要相告,使用的虽然是or,但表意却是and,即希望两者都知道.所以,用复数表示泛指.这个句子是可以换种思维来看的：If you see them,tell them about it——my teacher or my classmates.意指很明显.举个例子：Tom or his girls,they are all welcome here!(汤姆还是他的女儿们,这儿都欢迎他们来!)=They are all welcome here,Tom or his girls (equally)!