The sounds (very dangerous)对括号里的进行提问.---- ---- that sound?

题目

The sounds (very dangerous)对括号里的进行提问.---- ---- that sound?
we should help each other.(改为同义句）
It's--- --- --- --- --- each other.
The boy is a topo student in our class.He is thirteen ,(改为同义句）
The --- --- is a top sudent in our class

答案

better for us to help
boy thirteen