【单选题】—Where are his parents from? —They ________ from Nanjing. [ ]
【单选题】His English is improving _______, which makes both his parents and his teacher happy.
【单选题】—Which of his parents is a doctor?—______ are.
【单选题】He loves his parents deeply, ________ are very kind to him.
【单选题】The __________ of his books among parents and the recommendation of experts both at home and abroad have quickly made him a celebrity educator.