When you learn a foreign language, ________you must forget your own one.

He hasn’t slept at all for three days.____he is tired out.

As a teacher , we should try to _____ it ____ to our students how helpful a correct learning method is .

The medical team, three doctors and two nurses, _______ for the mountain area yesterday.

Many years of hard work_______ his great success in the development of this new type of material.