计算小数加减法时，先把各数的____对齐，再按照____进行计算．
38＋25=____
2000×4=____
505×1=____
(45＋55)×3=____
I don't think it is _____ useless competition, because it has offered us ____valuable experience for the next competition.
我国纬度最高的盆地是( )
下列各句中，没有语病的一项是（ ）
