请根据句意或括号中的中文提示、英文释义，写出句中所缺单词，使句子通顺。
1. The man laughed when he ______ (know or understand something that you did not know before) what had happened.
2. When I grow up, I will go ______ (国外) for further study.
3. That naughty boy drew a ______[kɑ：'tu：n] of his teacher on a piece of paper in class.
4. The apple pies made by my mother are really ______. ( tasty)
5. The poor dog lay there with its eyes closed, the master knew nobody could help it. It was already ______.