(2012·昆明高二检测)It is well-known that proper amounts of exercises, if _______ regularly, will benefit our health.

After the National Entrance Examination the students will have an anxious couple of weeks _____ for the results.

In many countries more and more forests and even agricultural land are being lost to development, _______ much of the land to become desert. 

 I often dream of jogging out with snow _______ the ground.

It is reported that the water in the river is becoming worse and worse, the river around the city ____ with waste from factories．