Tina_____haveknownthetruth,orshewouldhavetoldus.

It is no longer a problem _______ the poor children in this district can go to school.

InfactPeterwouldratherhaveleftforSanFranciscothan____inNewYork.

You____himsoclosely;youshouldhavekeptyourdistance.

The professor could hardly find sufficient grounds _____his arguments in favor of the new theory.