题目

一列客车长190米，每秒运行24米，在这列客车前面有一列货车长230米，每秒运行18米，两列车在并列的两条轨道上运行。客车从后面追上并完全超过货车要用多少秒? 答案：解：(190+230)÷(24-18)=70(秒)所以客车从后面追上并完全超过货车要用70秒.根据句意及图片提示或汉语提示完成单词。                                 (1)                        (2)                      (3)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.