口腔里食物的消化是由____、____、____共同完成。
第十六届亚运会获奖牌数前两名国家的奖牌情况统计图
— Jim took one-hour ride just now. What a short time he spent finishing such a long way!— He is experienced rider.
分式1x-1有意义,则x的取值范围是( )