你好。不是同位语结构。1He，short and thin，is unfit for the job． === As he is short and thin, he is unfit for the job----------原因状语从句2 All the countries，big or small，are equal===No matter they are big or small, all the countries are equal-------让步状语从句...
He,the engineer, also likes playing basketball . 他，这个工程师，也喜欢打篮球。short and thin, big of small 是形容词，只是对主语进行修饰， 所谓同位语就是对名词的解释说明，要与名词地位一样，比如我说的这句话里面 He also likes playing basketball....
