1.如果要说,老虎是危险的.以下几句,哪个对呢? Tigers are dangerous. The tiger is dangerous. A tiger is dangerous. 2.上面三句中,第二句固然是对的,各种语法书里也有这个例句,讲解是说,the 加可数名词单数,表示这一种类.如the tiger,表示虎类(世界上所有的虎),the woolf,狼类. 那么,the teacher 是否也表示教师这类人(世界上所有的老师)呢 比如下面这句 It is often said that( teachers have) an easy life. 括号内的是否可以换成1,the teacher has 2,a teacher has 3,the teachers have 表达的意思是否都一样呢?