The river was so deep that I couldn't see the bottom. → It was ________________ I couldn't see the bottom. (SUCH)
such a deep river that
It is easy to see why the Statue of Liberty is such a big attraction for tourists. → It is easy to see why the Statue of Liberty ___________ tourists. (SO)
is so attractive to
My sister is not old enough to ride a bike . → My sister is ___________ ride a bike. (TO)
too young to