依次填人下面一段文字横线处的语句，衔接最恰当的一组是（ ）留守儿童的命运越来越引起人们的广泛关注， ， ，， ， ， 。农村孩子“被留守”的个人命运，其实正是农村被甩脱的时代命运。①很多时候，“留守”实际就是“被甩脱”②农村为了追赶上时代发展的步伐③而是这个时代轰隆隆的列车正在无情地甩下农村④不是父母甩下了他们⑤又无奈地甩下了他们的孩子⑥客观地说，“留守”还是比较中性、温婉的说法

The pilot asked all the passengers on board to remain ______ as the plane was making a landing.

Teachers suggested parents theirchildren under 12 to ride bicycles to school for safety.

None of them could understand your meaning, _________?

286. — Can you __________ the hole in my trousers ? — Yes , of course. I learned to ______________ at school.