李师傅做了100个零件,合格率是95%,如果再做两个合格零件,那么合格率就达到97%。
—________your brother speak French?
—Yes, he has learnt it in Paris for three years.
下列是四位同学对一日天气的描述,你认为可信的是( )
在测量学生用课桌高度时,下列各种刻度尺中应该优先选择 ( )