1) They
were Norsemen of Scandinavia who in their ships braved Arctic seas to make
their way to Greenland in 985 AD.
to make -- an
adverbial modifier of purpose обстоятельство цели
2) Their
method of reading was to read one line from left to right, then to come back
and to read the next from right to left.
to read, to
come back, to read – part of a predicate (predicative) именная часть сказуемого
3) To
preserve the traditions under these circumstances was very difficult and they
were not preserved.
to preserve
-- subject подлежащее
4) The
right to organize a guild was granted to the first towns by the owner of the
land who might be the king, abbot or some other powerful lord.
to organize
-- attribute определение
be – part of a compound verbal modal predicate часть составного глагольного модального сказуемого