根据句意，用所给单词的适当形式填空。

1．There are too many new words in the         （twelve）unit．

2．What you've said is         （possible）true．

3．The longer people waited for help，the         （danger）the situation became．

4．Mike can still remember         （give）a bike as a present on his 18th birthday．

5．The government had some laws         （change）after the meeting．