万里长城和京杭大运河都是我国古代文明的伟大成就，其中纵贯南北的京杭大运河修建时长度大约为1 790 000米，是非常杰出的水利工程．将数据1 790 000米用科学记数法表示为____米．

如图，对△ABC分别作下列变换：①先以x轴为对称轴作轴对称图形，然后再向左平移4个单位；②以点O为中心顺时针旋转180°，然后再向左平移2个单位；③先以y轴为对称轴作对称图形，然后再向下平移3个单位；其中能使△ABC变成△DEF的是（　　）

根据短文内容，选择所给词的适当形式完成短文。                

The most important person in the world is your mother. She looks after you all the ____ .On cold winter days, she always tells you ____on more clothes. She always stands in the wind waiting for you back from school every day. When you hurry to leave home for school without breakfast, she always feels ____  about you at home. She knows about your study and spends much money ____ your school things. Mother can do everything for you day after day. What ____  love that is in the world! We’ll always remember mother love.