根据句意及图片提示或汉语提示完成单词。
1. There are many _____ (
) in the old house.
2. I often go to Beijing by _____ (
) with my father.
3. Before you go online, you must connect the _____ (
) to the computer.
4. Our teacher often _____ (检查) our homework in class.
5. The doctor _____ (挽救) many people's lives every year.