The charity sale our school organizes every year has taught us much. _______ we would never have learned it in class.

Day after day, they dragged their feet on and arrived at their destination ________. 

Noise is unpleasant, _____ when you are trying to sleep. 

Many people have found their reading skill_____ improved after some training.

It is well known to all that a machine needs fuel to run;    ,man needs food to live on.