阅读下面短文，在空白处填入一个恰当的单词或括号内所给单词的正确形式，并将答案写在答题卡上相应的横线上。
Everyone knows that second—hand smoke is as harmful as first—hand smoke.But have you （hear） of "third—hand" smoke？
Third—hand smoke means the （pollute） left on the surfaces of things，like sofas floors or clothes . This can cause great danger to your family，especially younger children.
Babies are （possible） to be harmed by third—hand smoke than others.This is they are often close to surfaces of things where tobacco particles （烟草颗粒） remain.When they touch these surfaces，they get （they） hands polluted.
So，it is important to say no to third—hand smoke.To achieve this，strict （rule） on stopping smoking inside homes should be （carry） out.If one of your family members smokes，please make sure he smokes outside the house.When the smoker finishes （smoke），make sure that he washes his hands and face before picking up the baby.
Many times，you can't see the smoke doing harm your children，but it doesn't mean they' re safe.Give up smoking，or make sure that your loved ones