His family _____ from him for six months until yesterday. [ ]

A. hasn't heard

B. didn't hear

C. hadn't heard

D. heard

患者，男性，62岁，甲状腺功能亢进5年。今日体温突然达40℃，心率150/min，恶心、呕吐、腹泻，大汗淋漓，昏睡。查FT₃及FT₄显著增高，诊断为甲状腺危象。产生该现象的原因是

A．感染使代谢增高
B．机体消耗大量甲状腺素
C．腺垂体功能亢进
D．大量甲状腺素释放入血
E．自主神经功能紊乱