时间单位中，比秒大的常用单位有天（d）、年（y），则1d=_______s。
86400
When he was a student, he would get up early and work late into night, believing “______________”
A．Never too late to learn.
B．Never count your chickens until they are hatched.
C．The early bird catches the worm.
D．Everyone has his feet of clay
女性臂肌围正常值为
A．20.9～25.5cmB．21.9～25.5cmC．22.9～25.5cmD．23.9～25.5cmE．22.8～27.8cm
