i brush my teeth twice a day 为什么要用teeth而不是tooth

I'm going to go brush my teeth 还是 I'm going to brush my teeth I always brush my teeth after supper.对划线部分提问 划线：brush my teeth brush my teeth brush my teeth是什么意思? 用teeth,always,yes,I,my,brush组句 I brush my teeth every day(用now改写句子) I brush my teeth twice every day 划 twice 提问 i brush my teeth every day.改一般疑问句 how mang times i brush my teeth every day I brush my teeth every morning 改一般疑问句 I brush my teeth before goingto bed.(同义句) I brush my teeth every night.(用NOW改写) brush my teeth怎么读 i brush my teeth twice a day 为什么要用teeth而不是tooth I’ve got to go brush my teeth.出处：还是：I’ve got to go brushing my teeth. first,i get up early.next,i brush my teeth and wash my face. 我正在刷牙.用英语怎么说?是I 'm brushing my teeth.还是I 'm brushing teeth.没有my行不行.为什么?另外这里的my是冠词吗?刷牙用英语说应该是brush teeth还是brush my teeth 为什么？ I brush my teeth and comb my hair.这句话有误吗?