If you swim in a river or lake, be sure to investigate is below the water surface. Often there are rocks or branched hidden in the water.
Only when your identity has been checked ___.
The computer was used in teaching. As a result, not only ___, but students became more interested in the lessons.
In such a hurry ___ to the railway station that they left their tickets behind at home.
Not until quite recently ___ that language is closely related to culture.
Only if ___ the examinations, ___ get the gift promised by your father.