单项选择题Some educators try to put students of similar abilities into the same class because they believe this kind of __________ grouping is advisable.
单项选择题Military orders are __________ and cannot be disobeyed.
单项选择题What you say now is not __________ with what you said last week.
单项选择题Many years had __________ before they returned to their original urban areas.
单项选择题All the people in the stadium cheered up when they saw hundreds of colorful balloons __________ slowly into the sky.