将99954精确到十位约是____,精确到百位约是____,精确到千位约是____.
gāo tang áo suàn shòu què
熬____ 糕____ 糖____ 确____ 算____ 售____
已知fx=a-x2-2xx<0fx-1x≥0且函数y=fx-x恰有3个不同的零点,则实数a的取值范围是( )
My shoes are under the bed, but ________ under the sofa.