5. The train delayed for 30 minutes.
火车延迟了30分钟。
还能这样说：
The train was 30 minutes late.
The train was 30 minutes behind schedule.
应用解析：
passenger train 客运列车;
goods train 货运列车
6. The train for Shanghai is on track 4.
开往上海的列车停靠在第四站台。
还能这样说：
The train for Shanghai is on platform 4.
The train for Shanghai leaves from track 4.
应用解析：
track events 径赛项目;
in one's tracks 就地，当场;
lose track of 失去踪迹，忘记;与……失去联系;
on the track 不离本题，正确
7. I think you are in my seat.
我想你坐的是我的座位。
还能这样说：
I think you take my seat.
I'm afraid you are in my seat.
应用解析：
driver's seat 驾驶员座;具有控制、指挥权力的职位;
resign one's seat 辞去职务
8. The train is driving after ten minutes.
列车定于10分钟后开车。
还能这样说：
The train leaves in ten minutes.
The train starts in ten minutes.
应用解析：
at the last minute 在紧要关头;
from one minute to the next 瞬息之间;
half a minute 片刻;
in a minute 马上，立刻;
make a minute of 记录，记下