范围
主传动系采用背轮机构,通过扩大变速组( )变速范围,来扩大传动系( )。
主传动系采用背轮机构,通过扩大变速组( )变速范围,来扩大传动系( )。极限;总变速范围
Of the two students, one is named Tom and another named Fred.
Of the two students, one is named Tom and another named Fred.