Aftermonthsofvoyage,Columbusarrivedin______laterprovedtobeanewcontinent.
C
注意， 本句话并非定语从句， 而是宾语从句。 因为在介词 in 后面，应该用 what 引导的宾语从句， what 在宾语从句中作主语。
He was ______ to withdraw from running for the presidency.
Iftheoperation________carefullyprepared,itwouldnothavebeensuccessful.