on average, in other words, concentrate on, come up with, at a disadvantage
1. There were so many people talking in the classroom that I couldn't my study.
2. His inability to speak French puts him .
3. We will discuss the strange idea you this afternoon.
4. ― You must have a high income doing that kind of job.
―Oh,my income is not set,but I earn 100yuan a day .
5. While you are driving,you must concentrate. ,don't let anyone or anything disturb you.