It be the vocabulary that caused you the problem in the exercise because you know a lot of words.
Whatever is left over may be put into the refrigerator, ______ it will keep for two or three weeks.
Care of the soul is a gradual process ______ even the small details of life should be considered.
Maria has written two novels, both of ______ have been made into television series.
It is the third time that she has won the race, _______ has surprised us all.
John knows so much about the film star that I am sure it would be impossible to find his ____.