Maria came ____ (猛冲,突进) down the stairs as soon as she heard her mother back home.
用乘法分配律计算下面各题
①103×12=
②20×55 =
③4600÷25÷4=
④136×101-136 =
“爱党爱国、助人为乐、敬业奉献、锐意创新、艰苦奋斗”的雷锋精神,是中国社会主义建设时期中华民族精神的突出表现。弘扬和培育这一民族精神是提高全民族综合素质的必然要求,因为这一精神( )