The soldiers bowed their heads in ______(恭敬) silence as the funeral procession(葬礼队伍) went by.
Try to be more __________（积极）in dealing with the problem.
A __________（激烈的）debate on the tax cut was going on.
If the sun were to __________（消失），what would the earth be like?
These teaching materials can be __________（改编）for older children.
Mr Smith __________ __________ __________ attend the meeting because he is too busy. （不可能）