... very thick / belong / younger sister A That book, what is very thick, belongs to my younger sister B That book, that is very thick, belongs to my younger sister C That book, which is very thick, ... very thick / belong / younger sister A That book, what is very thick, belongs to my younger sister B That book, that is very thick, belongs to my younger sister C That book, which is very thick, ... this practice shouldn’t become an accepted social custom The old couples’ expense on food has already increased while young couples spend more on clothing and furnishing and less on food If this...