根据下列句子及所给汉语注释，在句子右边的横线上写出空缺处各单词的正确形式。（每空只写一词）

小题1:Only then did I realize the _____________(重要性) of learning English.

小题2:All countries, big or small, should be ___________.(平等)

小题3:The ___________(狭窄的) high way should be broadened.

小题4:__________(幸运地)， he passed the exam successfully.

小题5:He _____________(经历) a terrible traffic accident last month.

小题6:With the _____________(发展) of the economy, more and more people buy private cars.

小题7:We will remove the ______________(家具) from our house.

小题8:A policeman asked: “What _____________(引起) the fire in the hotel?”

小题9:The meeting will be held on next ____________ (星期三).

小题10:We must do something to reduce the air ________________.（污染）

除尘工作中的“水”“密”“封”是什么内容？