什么叫心率，高中生的正常心率是多少？
参考答案：心率是指每分钟心跳的次数，高中生的正常心率78次/min。
His arms were sunburnt because he in the sun all day.
A．had sat
B．sat
C．is sitting
D．had been sitting
甲状腺髓样癌
