–In the old days, most teenages had to work for the landlord(地主)in the field to help their families, because their families couldn’t education for them.-What a pity!
________ you've got a headache. You drank too much last night.
In those days, books could only be produced one at a time by hand. __________, they were expensive and rare.
It is clever ________ you ________ me work out the maths problem.
There is ________ in the classroom, so we can see ________.
We should prevent the children ________ the bad programmes.