据汉意或首字母的提示，填写所缺的单词。
1. Yesterday I______ (睡过头了), I was late for school.
2. Alexander Graham Bell i______ the telephone in 1876.
3. Do you know how to o______ on the machine?
4. Have you b_____ the baby's milk yet?
5. The doctor didn't ______ (披露) the truth to him.
