Time is the easiest thing in the world to waste and the most difficult thing to control.
On the average， men are higher than women by several inches/several inches higher than women.
The test was much more difficult than we had expected.
It is well known that even the same leisure activity may be used differently by different individuals.
The patient is said to have asked the doctor to help him die.
Operations that were considered impossible a few years ago can now be performed in many hospitals.
Most of the major medical advances are based on animal research.
The singer was accompanied on the piano by his pupil.
We hurried back to school lest it should rain.
Three years age she used to work for a very low wage at a tea factory in London.
Will there be any difference between the mental and the manual labor in the future？
The police have taken a detailed and comprehensive investigation into the case.
People have different ideas／views about how to attain the goal.
The problem now is not what to read，but how to read.
At that time it was folk music that was popular among college students.