Smile to the world, ___________ the world will smile back to you.

If you first aid correctly, the man would have not hurt that much.[ ]

The rescue team has saved more than ten people________under the collapsed buildings since the earthquake occurred in Ya’an.

下列各句中，划线的成语使用恰当的一项是（ ）

____, most teenagers now listen to rock music.However, John likes classical music better[ ]