As soon as his teacher begins lecturing, he begins to doze off, not intentionally but _____.
Young people should go ____ working conditions are difficult.
On a peaceful summer day, he went to swim in the sea _____.
Those who have trouble _____ can grow crops vertically on trellises.
An excellent company is good at providing its employees and co-workers with a ____which makes them feel at home.
It is _______ that you understand what type of soil you have in your garden before you can take steps to improve it.