There are three staff members in an office: Liu Ming, Zhuang Yan, and Wen Hu. Among them, one is a Ph. D. , one is a master, and one is an undergraduate. It is known that the doctor is two years older than Liu Ming; Zhuang Yan and undergraduate Graduates are the same age, but with slightly older months; undergraduate graduates are the youngest. From this, can it be launched? ['Liu Ming is an undergraduate, Zhuang Yan is a master, and Wen Hu is a doctor.', 'Liu Ming is a master, Zhuang Yan is a doctor, and Wen Hu is an undergraduate.', 'Liu Ming is an undergraduate, Zhuang Yan is a Ph. D. , Wenhu is a master.', 'Liu Ming is a master, Zhuang Yan is an undergraduate, and Wen Hu is a doctor.']