选用下列所给的词并用其适当形式填空。（5分）
| laugh at own learn from careful escape |
66. I don’t know whose watch it is? So I’m waiting for the ______________.
67. Last week a lion ____________from the zoo. It hasn’t been found yet.
68. We should ______________ each other and help each other.
69. Don’t _______________other people. It’s impolite.
70. Our teachers ask us to listen ______________in class.